#!/usr/bin/env python3 import sys sys.set_int_max_str_digits(16000) def fact(n): ret = 1 for i in range(1, n + 1): ret *= i; return ret def count_zeros(n): ln = len(str(n)) return ln - len(str(n).rstrip('0')) for i in range(1, 4001): tmp = fact(i) print(f"{i} : {count_zeros(tmp)} | {(i // 5) + (i // 25) + (i // 125)}")