Removed some empty *.cpp files and Solved some new problems

13 files changed, 860 insertions, 0 deletions

diff --git a/contests/Round887/A/main b/contests/Round887/A/main
new file mode 100755
index 0000000..41b5468
--- /dev/null
+++ b/contests/Round887/A/main
diff --git a/contests/Round887/A/main.cpp b/contests/Round887/A/main.cpp
new file mode 100755
index 0000000..b645809
--- /dev/null
+++ b/contests/Round887/A/main.cpp
@@ -0,0 +1,152 @@
+#include <bits/stdc++.h>
+using namespace std;
+
+using ll = long long;
+using pii = pair<int, int>;
+using vpi = vector<pii>;
+using vi = vector<int>;
+using vll = vector<long long>;
+using mpii = map<int, int>;
+using mpll = map<ll, ll>;
+using db = long double;
+
+#define pb push_back
+#define all(x) (x).begin(), (x).end()
+#define rall(x) (x).rbegin(), (x).rend()
+#define lb lower_bound
+#define ub upper_bound
+#define make_unique(x)                                                         \
+  sort(all((x)));                                                              \
+  (x).resize(unique(all((x))) - (x).begin())
+#define ceil(a, b) ((a) + (b) - 1) / (b))
+
+const int MOD = (int)1e9 + 7;
+const db PI = acos((db)-1);
+const int dx[4]{1, 0, -1, 0};
+const int dy[4]{0, 1, 0, -1};
+
+template <typename K, typename V>
+ostream &operator<<(ostream &os, const pair<K, V> &p);
+template <typename T> ostream &operator<<(ostream &os, const vector<T> &vec);
+template <typename K, typename V>
+ostream &operator<<(ostream &os, const map<K, V> &m);
+template <typename K, typename V>
+ostream &operator<<(ostream &os, const unordered_map<K, V> &m);
+template <typename T> ostream &operator<<(ostream &os, const set<T> &s);
+template <typename T>
+ostream &operator<<(ostream &os, const unordered_set<T> &s);
+
+template <typename K, typename V>
+ostream &operator<<(ostream &os, const pair<K, V> &p) {
+  os << "(" << p.first << ", " << p.second << ")";
+  return os;
+}
+
+template <typename T> ostream &operator<<(ostream &os, const vector<T> &vec) {
+  os << "{";
+  for (size_t i = 0; i < vec.size(); ++i) {
+    if (i > 0)
+      os << ", ";
+    os << vec[i];
+  }
+  os << "}";
+  return os;
+}
+
+template <typename K, typename V>
+ostream &operator<<(ostream &os, const map<K, V> &m) {
+  os << "{";
+  for (const auto &p : m) {
+    os << p.first << ": " << p.second << ", ";
+  }
+  os << "}";
+  return os;
+}
+
+template <typename K, typename V>
+ostream &operator<<(ostream &os, const unordered_map<K, V> &m) {
+  os << "{";
+  for (const auto &p : m) {
+    os << p.first << ": " << p.second << ", ";
+  }
+  os << "}";
+  return os;
+}
+
+template <typename T> ostream &operator<<(ostream &os, const set<T> &s) {
+  int i = 0;
+  os << "{";
+  for (const auto &e : s) {
+    if (i > 0)
+      os << ", ";
+    os << e;
+    i++;
+  }
+  os << "}";
+  return os;
+}
+
+template <typename T>
+ostream &operator<<(ostream &os, const unordered_set<T> &s) {
+  int i = 0;
+  os << "{";
+  for (const auto &e : s) {
+    if (i > 0)
+      os << ", ";
+    os << e;
+    i++;
+  }
+  os << "}";
+  return os;
+}
+
+void dbg() { cerr << "\n"; }
+
+template <typename T, typename... TS> void dbg(T val, TS... vals) {
+  cerr << val << " ";
+  dbg(vals...);
+}
+
+/* stuff you should look for:
+  ---------------------------
+   * special cases (n=1?)
+   * int overflow, array bounds
+   * do smth instead of nothing and stay organized
+   * WRITE STUFF DOWN
+   * DON'T GET STUCK ON ONE APPROACH
+ */
+
+void solve() {
+  int n;
+  cin >> n;
+  vi v(n);
+  for (auto &x : v) {
+    cin >> x;
+  }
+
+  if (!is_sorted(all(v))) {
+    cout << 0 << '\n';
+    return;
+  }
+  int mn = INT_MAX;
+  for (int i = 0; i < n - 1; i++) {
+    mn = min(mn, v[i + 1] - v[i]);
+  }
+
+  if (mn == 0) {
+    cout << 1 << '\n';
+    return;
+  }
+
+  cout << (mn / 2) + 1 << '\n';
+}
+
+int main() {
+  ios_base::sync_with_stdio(false);
+  cin.tie(NULL);
+  int tt;
+  cin >> tt;
+  while (tt--) {
+    solve();
+  }
+}
diff --git a/contests/Round887/A/main_input0.txt b/contests/Round887/A/main_input0.txt
new file mode 100644
index 0000000..b0e13f0
--- /dev/null
+++ b/contests/Round887/A/main_input0.txt
@@ -0,0 +1,9 @@
+4
+2
+1 1
+4
+1 8 10 13
+3
+1 3 2
+3
+1 9 14
diff --git a/contests/Round887/A/main_output0.txt b/contests/Round887/A/main_output0.txt
new file mode 100644
index 0000000..a2c2ab8
--- /dev/null
+++ b/contests/Round887/A/main_output0.txt
@@ -0,0 +1,4 @@
+1
+2
+0
+3
diff --git a/contests/Round887/B/gen.py b/contests/Round887/B/gen.py
new file mode 100644
index 0000000..7cdb534
--- /dev/null
+++ b/contests/Round887/B/gen.py
@@ -0,0 +1,4 @@
+import sys
+
+for i in range((int(sys.argv[1]) // 2) + 1):
+    print(i, int(sys.argv[1]) - i)
diff --git a/contests/Round887/B/main b/contests/Round887/B/main
new file mode 100755
index 0000000..1ca1e08
--- /dev/null
+++ b/contests/Round887/B/main
diff --git a/contests/Round887/B/main.cpp b/contests/Round887/B/main.cpp
new file mode 100755
index 0000000..20406b3
--- /dev/null
+++ b/contests/Round887/B/main.cpp
@@ -0,0 +1,158 @@
+#include <bits/stdc++.h>
+using namespace std;
+
+using ll = long long;
+using pii = pair<int, int>;
+using vpi = vector<pii>;
+using vi = vector<int>;
+using vll = vector<long long>;
+using mpii = map<int, int>;
+using mpll = map<ll, ll>;
+using db = long double;
+
+#define pb push_back
+#define all(x) (x).begin(), (x).end()
+#define rall(x) (x).rbegin(), (x).rend()
+#define lb lower_bound
+#define ub upper_bound
+#define make_unique(x)                                                         \
+  sort(all((x)));                                                              \
+  (x).resize(unique(all((x))) - (x).begin())
+#define ceil(a, b) ((a) + (b) - 1) / (b))
+
+const int MOD = (int)1e9 + 7;
+const db PI = acos((db)-1);
+const int dx[4]{1, 0, -1, 0};
+const int dy[4]{0, 1, 0, -1};
+
+template <typename K, typename V>
+ostream &operator<<(ostream &os, const pair<K, V> &p);
+template <typename T> ostream &operator<<(ostream &os, const vector<T> &vec);
+template <typename K, typename V>
+ostream &operator<<(ostream &os, const map<K, V> &m);
+template <typename K, typename V>
+ostream &operator<<(ostream &os, const unordered_map<K, V> &m);
+template <typename T> ostream &operator<<(ostream &os, const set<T> &s);
+template <typename T>
+ostream &operator<<(ostream &os, const unordered_set<T> &s);
+
+template <typename K, typename V>
+ostream &operator<<(ostream &os, const pair<K, V> &p) {
+  os << "(" << p.first << ", " << p.second << ")";
+  return os;
+}
+
+template <typename T> ostream &operator<<(ostream &os, const vector<T> &vec) {
+  os << "{";
+  for (size_t i = 0; i < vec.size(); ++i) {
+    if (i > 0)
+      os << ", ";
+    os << vec[i];
+  }
+  os << "}";
+  return os;
+}
+
+template <typename K, typename V>
+ostream &operator<<(ostream &os, const map<K, V> &m) {
+  os << "{";
+  for (const auto &p : m) {
+    os << p.first << ": " << p.second << ", ";
+  }
+  os << "}";
+  return os;
+}
+
+template <typename K, typename V>
+ostream &operator<<(ostream &os, const unordered_map<K, V> &m) {
+  os << "{";
+  for (const auto &p : m) {
+    os << p.first << ": " << p.second << ", ";
+  }
+  os << "}";
+  return os;
+}
+
+template <typename T> ostream &operator<<(ostream &os, const set<T> &s) {
+  int i = 0;
+  os << "{";
+  for (const auto &e : s) {
+    if (i > 0)
+      os << ", ";
+    os << e;
+    i++;
+  }
+  os << "}";
+  return os;
+}
+
+template <typename T>
+ostream &operator<<(ostream &os, const unordered_set<T> &s) {
+  int i = 0;
+  os << "{";
+  for (const auto &e : s) {
+    if (i > 0)
+      os << ", ";
+    os << e;
+    i++;
+  }
+  os << "}";
+  return os;
+}
+
+void dbg() { cerr << "\n"; }
+
+template <typename T, typename... TS> void dbg(T val, TS... vals) {
+  cerr << val << " ";
+  dbg(vals...);
+}
+
+/* stuff you should look for:
+  ---------------------------
+   * special cases (n=1?)
+   * int overflow, array bounds
+   * do smth instead of nothing and stay organized
+   * WRITE STUFF DOWN
+   * DON'T GET STUCK ON ONE APPROACH
+ */
+
+// 55 34 21
+
+int fib(int n, int m) {
+  int ans = 1;
+  while (n - m >= 0) {
+    ans++;
+    // dbg(n, m);
+    int tmp = n;
+    n = m;
+    m = tmp - n;
+  }
+  return ans;
+}
+
+void solve() {
+  int n, k;
+  cin >> n >> k;
+  int ans = 0;
+  for (int i = 0; i < (n / 2) + 1; i++) {
+    if (n == 22) {
+      dbg(n - i, i);
+      dbg(fib(n - i, i));
+      dbg("---------------");
+    }
+    if (fib(n - i, i) >= k - 1) {
+      ans++;
+    }
+  }
+  cout << ans << '\n';
+}
+
+int main() {
+  ios_base::sync_with_stdio(false);
+  cin.tie(NULL);
+  int tt;
+  cin >> tt;
+  while (tt--) {
+    solve();
+  }
+}
diff --git a/contests/Round887/B/main_input0.txt b/contests/Round887/B/main_input0.txt
new file mode 100644
index 0000000..5687cc8
--- /dev/null
+++ b/contests/Round887/B/main_input0.txt
@@ -0,0 +1,9 @@
+8
+22 4
+3 9
+55 11
+42069 6
+69420 4
+69 1434
+1 3
+1 4
diff --git a/contests/Round887/B/main_output0.txt b/contests/Round887/B/main_output0.txt
new file mode 100644
index 0000000..bb5e1c9
--- /dev/null
+++ b/contests/Round887/B/main_output0.txt
@@ -0,0 +1,8 @@
+4
+0
+1
+1052
+11571
+0
+1
+0
diff --git a/contests/Round887/C/main.cpp b/contests/Round887/C/main.cpp
new file mode 100755
index 0000000..20800e5
--- /dev/null
+++ b/contests/Round887/C/main.cpp
@@ -0,0 +1,129 @@
+#include <bits/stdc++.h>
+using namespace std;
+
+using ll = long long;
+using pii = pair<int, int>;
+using vpi = vector<pii>;
+using vi = vector<int>;
+using vll = vector<long long>;
+using mpii = map<int, int>;
+using mpll = map<ll, ll>;
+using db = long double;
+
+#define pb push_back
+#define all(x) (x).begin(), (x).end()
+#define rall(x) (x).rbegin(), (x).rend()
+#define lb lower_bound
+#define ub upper_bound
+#define make_unique(x)                                                         \
+  sort(all((x)));                                                              \
+  (x).resize(unique(all((x))) - (x).begin())
+#define ceil(a, b) ((a) + (b) - 1) / (b))
+
+const int MOD = (int)1e9 + 7;
+const db PI = acos((db)-1);
+const int dx[4]{1, 0, -1, 0};
+const int dy[4]{0, 1, 0, -1};
+
+template <typename K, typename V>
+ostream &operator<<(ostream &os, const pair<K, V> &p);
+template <typename T> ostream &operator<<(ostream &os, const vector<T> &vec);
+template <typename K, typename V>
+ostream &operator<<(ostream &os, const map<K, V> &m);
+template <typename K, typename V>
+ostream &operator<<(ostream &os, const unordered_map<K, V> &m);
+template <typename T> ostream &operator<<(ostream &os, const set<T> &s);
+template <typename T>
+ostream &operator<<(ostream &os, const unordered_set<T> &s);
+
+template <typename K, typename V>
+ostream &operator<<(ostream &os, const pair<K, V> &p) {
+  os << "(" << p.first << ", " << p.second << ")";
+  return os;
+}
+
+template <typename T> ostream &operator<<(ostream &os, const vector<T> &vec) {
+  os << "{";
+  for (size_t i = 0; i < vec.size(); ++i) {
+    if (i > 0)
+      os << ", ";
+    os << vec[i];
+  }
+  os << "}";
+  return os;
+}
+
+template <typename K, typename V>
+ostream &operator<<(ostream &os, const map<K, V> &m) {
+  os << "{";
+  for (const auto &p : m) {
+    os << p.first << ": " << p.second << ", ";
+  }
+  os << "}";
+  return os;
+}
+
+template <typename K, typename V>
+ostream &operator<<(ostream &os, const unordered_map<K, V> &m) {
+  os << "{";
+  for (const auto &p : m) {
+    os << p.first << ": " << p.second << ", ";
+  }
+  os << "}";
+  return os;
+}
+
+template <typename T> ostream &operator<<(ostream &os, const set<T> &s) {
+  int i = 0;
+  os << "{";
+  for (const auto &e : s) {
+    if (i > 0)
+      os << ", ";
+    os << e;
+    i++;
+  }
+  os << "}";
+  return os;
+}
+
+template <typename T>
+ostream &operator<<(ostream &os, const unordered_set<T> &s) {
+  int i = 0;
+  os << "{";
+  for (const auto &e : s) {
+    if (i > 0)
+      os << ", ";
+    os << e;
+    i++;
+  }
+  os << "}";
+  return os;
+}
+
+void dbg() { cerr << "\n"; }
+
+template <typename T, typename... TS> void dbg(T val, TS... vals) {
+  cerr << val << " ";
+  dbg(vals...);
+}
+
+/* stuff you should look for:
+  ---------------------------
+   * special cases (n=1?)
+   * int overflow, array bounds
+   * do smth instead of nothing and stay organized
+   * WRITE STUFF DOWN
+   * DON'T GET STUCK ON ONE APPROACH
+ */
+
+void solve() {}
+
+int main() {
+  ios_base::sync_with_stdio(false);
+  cin.tie(NULL);
+  int tt;
+  cin >> tt;
+  while (tt--) {
+    solve();
+  }
+}
diff --git a/contests/Round887/D/main.cpp b/contests/Round887/D/main.cpp
new file mode 100755
index 0000000..20800e5
--- /dev/null
+++ b/contests/Round887/D/main.cpp
@@ -0,0 +1,129 @@
+#include <bits/stdc++.h>
+using namespace std;
+
+using ll = long long;
+using pii = pair<int, int>;
+using vpi = vector<pii>;
+using vi = vector<int>;
+using vll = vector<long long>;
+using mpii = map<int, int>;
+using mpll = map<ll, ll>;
+using db = long double;
+
+#define pb push_back
+#define all(x) (x).begin(), (x).end()
+#define rall(x) (x).rbegin(), (x).rend()
+#define lb lower_bound
+#define ub upper_bound
+#define make_unique(x)                                                         \
+  sort(all((x)));                                                              \
+  (x).resize(unique(all((x))) - (x).begin())
+#define ceil(a, b) ((a) + (b) - 1) / (b))
+
+const int MOD = (int)1e9 + 7;
+const db PI = acos((db)-1);
+const int dx[4]{1, 0, -1, 0};
+const int dy[4]{0, 1, 0, -1};
+
+template <typename K, typename V>
+ostream &operator<<(ostream &os, const pair<K, V> &p);
+template <typename T> ostream &operator<<(ostream &os, const vector<T> &vec);
+template <typename K, typename V>
+ostream &operator<<(ostream &os, const map<K, V> &m);
+template <typename K, typename V>
+ostream &operator<<(ostream &os, const unordered_map<K, V> &m);
+template <typename T> ostream &operator<<(ostream &os, const set<T> &s);
+template <typename T>
+ostream &operator<<(ostream &os, const unordered_set<T> &s);
+
+template <typename K, typename V>
+ostream &operator<<(ostream &os, const pair<K, V> &p) {
+  os << "(" << p.first << ", " << p.second << ")";
+  return os;
+}
+
+template <typename T> ostream &operator<<(ostream &os, const vector<T> &vec) {
+  os << "{";
+  for (size_t i = 0; i < vec.size(); ++i) {
+    if (i > 0)
+      os << ", ";
+    os << vec[i];
+  }
+  os << "}";
+  return os;
+}
+
+template <typename K, typename V>
+ostream &operator<<(ostream &os, const map<K, V> &m) {
+  os << "{";
+  for (const auto &p : m) {
+    os << p.first << ": " << p.second << ", ";
+  }
+  os << "}";
+  return os;
+}
+
+template <typename K, typename V>
+ostream &operator<<(ostream &os, const unordered_map<K, V> &m) {
+  os << "{";
+  for (const auto &p : m) {
+    os << p.first << ": " << p.second << ", ";
+  }
+  os << "}";
+  return os;
+}
+
+template <typename T> ostream &operator<<(ostream &os, const set<T> &s) {
+  int i = 0;
+  os << "{";
+  for (const auto &e : s) {
+    if (i > 0)
+      os << ", ";
+    os << e;
+    i++;
+  }
+  os << "}";
+  return os;
+}
+
+template <typename T>
+ostream &operator<<(ostream &os, const unordered_set<T> &s) {
+  int i = 0;
+  os << "{";
+  for (const auto &e : s) {
+    if (i > 0)
+      os << ", ";
+    os << e;
+    i++;
+  }
+  os << "}";
+  return os;
+}
+
+void dbg() { cerr << "\n"; }
+
+template <typename T, typename... TS> void dbg(T val, TS... vals) {
+  cerr << val << " ";
+  dbg(vals...);
+}
+
+/* stuff you should look for:
+  ---------------------------
+   * special cases (n=1?)
+   * int overflow, array bounds
+   * do smth instead of nothing and stay organized
+   * WRITE STUFF DOWN
+   * DON'T GET STUCK ON ONE APPROACH
+ */
+
+void solve() {}
+
+int main() {
+  ios_base::sync_with_stdio(false);
+  cin.tie(NULL);
+  int tt;
+  cin >> tt;
+  while (tt--) {
+    solve();
+  }
+}
diff --git a/contests/Round887/E/main.cpp b/contests/Round887/E/main.cpp
new file mode 100755
index 0000000..20800e5
--- /dev/null
+++ b/contests/Round887/E/main.cpp
@@ -0,0 +1,129 @@
+#include <bits/stdc++.h>
+using namespace std;
+
+using ll = long long;
+using pii = pair<int, int>;
+using vpi = vector<pii>;
+using vi = vector<int>;
+using vll = vector<long long>;
+using mpii = map<int, int>;
+using mpll = map<ll, ll>;
+using db = long double;
+
+#define pb push_back
+#define all(x) (x).begin(), (x).end()
+#define rall(x) (x).rbegin(), (x).rend()
+#define lb lower_bound
+#define ub upper_bound
+#define make_unique(x)                                                         \
+  sort(all((x)));                                                              \
+  (x).resize(unique(all((x))) - (x).begin())
+#define ceil(a, b) ((a) + (b) - 1) / (b))
+
+const int MOD = (int)1e9 + 7;
+const db PI = acos((db)-1);
+const int dx[4]{1, 0, -1, 0};
+const int dy[4]{0, 1, 0, -1};
+
+template <typename K, typename V>
+ostream &operator<<(ostream &os, const pair<K, V> &p);
+template <typename T> ostream &operator<<(ostream &os, const vector<T> &vec);
+template <typename K, typename V>
+ostream &operator<<(ostream &os, const map<K, V> &m);
+template <typename K, typename V>
+ostream &operator<<(ostream &os, const unordered_map<K, V> &m);
+template <typename T> ostream &operator<<(ostream &os, const set<T> &s);
+template <typename T>
+ostream &operator<<(ostream &os, const unordered_set<T> &s);
+
+template <typename K, typename V>
+ostream &operator<<(ostream &os, const pair<K, V> &p) {
+  os << "(" << p.first << ", " << p.second << ")";
+  return os;
+}
+
+template <typename T> ostream &operator<<(ostream &os, const vector<T> &vec) {
+  os << "{";
+  for (size_t i = 0; i < vec.size(); ++i) {
+    if (i > 0)
+      os << ", ";
+    os << vec[i];
+  }
+  os << "}";
+  return os;
+}
+
+template <typename K, typename V>
+ostream &operator<<(ostream &os, const map<K, V> &m) {
+  os << "{";
+  for (const auto &p : m) {
+    os << p.first << ": " << p.second << ", ";
+  }
+  os << "}";
+  return os;
+}
+
+template <typename K, typename V>
+ostream &operator<<(ostream &os, const unordered_map<K, V> &m) {
+  os << "{";
+  for (const auto &p : m) {
+    os << p.first << ": " << p.second << ", ";
+  }
+  os << "}";
+  return os;
+}
+
+template <typename T> ostream &operator<<(ostream &os, const set<T> &s) {
+  int i = 0;
+  os << "{";
+  for (const auto &e : s) {
+    if (i > 0)
+      os << ", ";
+    os << e;
+    i++;
+  }
+  os << "}";
+  return os;
+}
+
+template <typename T>
+ostream &operator<<(ostream &os, const unordered_set<T> &s) {
+  int i = 0;
+  os << "{";
+  for (const auto &e : s) {
+    if (i > 0)
+      os << ", ";
+    os << e;
+    i++;
+  }
+  os << "}";
+  return os;
+}
+
+void dbg() { cerr << "\n"; }
+
+template <typename T, typename... TS> void dbg(T val, TS... vals) {
+  cerr << val << " ";
+  dbg(vals...);
+}
+
+/* stuff you should look for:
+  ---------------------------
+   * special cases (n=1?)
+   * int overflow, array bounds
+   * do smth instead of nothing and stay organized
+   * WRITE STUFF DOWN
+   * DON'T GET STUCK ON ONE APPROACH
+ */
+
+void solve() {}
+
+int main() {
+  ios_base::sync_with_stdio(false);
+  cin.tie(NULL);
+  int tt;
+  cin >> tt;
+  while (tt--) {
+    solve();
+  }
+}
diff --git a/contests/Round887/F/main.cpp b/contests/Round887/F/main.cpp
new file mode 100755
index 0000000..20800e5
--- /dev/null
+++ b/contests/Round887/F/main.cpp
@@ -0,0 +1,129 @@
+#include <bits/stdc++.h>
+using namespace std;
+
+using ll = long long;
+using pii = pair<int, int>;
+using vpi = vector<pii>;
+using vi = vector<int>;
+using vll = vector<long long>;
+using mpii = map<int, int>;
+using mpll = map<ll, ll>;
+using db = long double;
+
+#define pb push_back
+#define all(x) (x).begin(), (x).end()
+#define rall(x) (x).rbegin(), (x).rend()
+#define lb lower_bound
+#define ub upper_bound
+#define make_unique(x)                                                         \
+  sort(all((x)));                                                              \
+  (x).resize(unique(all((x))) - (x).begin())
+#define ceil(a, b) ((a) + (b) - 1) / (b))
+
+const int MOD = (int)1e9 + 7;
+const db PI = acos((db)-1);
+const int dx[4]{1, 0, -1, 0};
+const int dy[4]{0, 1, 0, -1};
+
+template <typename K, typename V>
+ostream &operator<<(ostream &os, const pair<K, V> &p);
+template <typename T> ostream &operator<<(ostream &os, const vector<T> &vec);
+template <typename K, typename V>
+ostream &operator<<(ostream &os, const map<K, V> &m);
+template <typename K, typename V>
+ostream &operator<<(ostream &os, const unordered_map<K, V> &m);
+template <typename T> ostream &operator<<(ostream &os, const set<T> &s);
+template <typename T>
+ostream &operator<<(ostream &os, const unordered_set<T> &s);
+
+template <typename K, typename V>
+ostream &operator<<(ostream &os, const pair<K, V> &p) {
+  os << "(" << p.first << ", " << p.second << ")";
+  return os;
+}
+
+template <typename T> ostream &operator<<(ostream &os, const vector<T> &vec) {
+  os << "{";
+  for (size_t i = 0; i < vec.size(); ++i) {
+    if (i > 0)
+      os << ", ";
+    os << vec[i];
+  }
+  os << "}";
+  return os;
+}
+
+template <typename K, typename V>
+ostream &operator<<(ostream &os, const map<K, V> &m) {
+  os << "{";
+  for (const auto &p : m) {
+    os << p.first << ": " << p.second << ", ";
+  }
+  os << "}";
+  return os;
+}
+
+template <typename K, typename V>
+ostream &operator<<(ostream &os, const unordered_map<K, V> &m) {
+  os << "{";
+  for (const auto &p : m) {
+    os << p.first << ": " << p.second << ", ";
+  }
+  os << "}";
+  return os;
+}
+
+template <typename T> ostream &operator<<(ostream &os, const set<T> &s) {
+  int i = 0;
+  os << "{";
+  for (const auto &e : s) {
+    if (i > 0)
+      os << ", ";
+    os << e;
+    i++;
+  }
+  os << "}";
+  return os;
+}
+
+template <typename T>
+ostream &operator<<(ostream &os, const unordered_set<T> &s) {
+  int i = 0;
+  os << "{";
+  for (const auto &e : s) {
+    if (i > 0)
+      os << ", ";
+    os << e;
+    i++;
+  }
+  os << "}";
+  return os;
+}
+
+void dbg() { cerr << "\n"; }
+
+template <typename T, typename... TS> void dbg(T val, TS... vals) {
+  cerr << val << " ";
+  dbg(vals...);
+}
+
+/* stuff you should look for:
+  ---------------------------
+   * special cases (n=1?)
+   * int overflow, array bounds
+   * do smth instead of nothing and stay organized
+   * WRITE STUFF DOWN
+   * DON'T GET STUCK ON ONE APPROACH
+ */
+
+void solve() {}
+
+int main() {
+  ios_base::sync_with_stdio(false);
+  cin.tie(NULL);
+  int tt;
+  cin >> tt;
+  while (tt--) {
+    solve();
+  }
+}