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#include <bits/stdc++.h> using namespace std; int main() { ios_base::sync_with_stdio(false); cin.tie(NULL); int tt; cin >> tt; while (tt--) { int l, r; cin >> l >> r; int foo = abs(r - l) + 1; cout << (l == r ? 1 : (foo * (foo + 1)) / 2) << '\n'; } }