func_code_string: #include <bits/stdc++.h>   using namespace std;   const long long inf = 1e17;   const int MAXM = 1e5 + 5;   const int MAXN = 1e6 + 4;   long long fact[MAXM];   long long nChoosek(long long n, long long k) {     if (k > n) return 0;     if (k * 2 > n) k = n - k;     if (k == 0) return 1;     long long result = n;     for (long long i = 2; i <= k; ++i) {       result *= (n - i + 1);       result /= i;     }     return result;   }   int main() {     long long n;     cin >> n;     long long Ans = 0;     for (long long i = 5; i <= 7; i++) {       Ans += nChoosek(n, i);     }     cout << Ans << endl;     return 0;   }   