#include <bits/stdc++.h>   using namespace std;   const long long N = 200005;   int main() {     long long n, z, x, y;     cin >> n;     z = (n * (n - 1) * (n - 2) * (n - 3) * (n - 4)) / 120;     x = (z * (n - 5)) / 6;     y = (x * (n - 6)) / 7;     cout << z + x + y <<   n ;     return 0;   }   