#include <bits/stdc++.h> #define int long long using namespace std; signed main() { int n; cin >> n; int ans = 1; int s = 0; for (int i = 2; ; i++) { s += i; if (n - s <= i) { ans *= n - s + i; s = n; break; } ans *= i; } printf("%lld\n",ans); return 0; }