func_code_string: #include <bits/stdc++.h>   using namespace std;   int ntest = 0, test = 0;   inline void init();   inline void run();   inline void stop() { ntest = test - 1; }   int main() {     init();     while (++test <= ntest) {       run();     }     return 0;   }   const int INF = (int)1E9 + 5;   const double EPS = 1E-11;   const long long MOD = (long long)1E9 + 7;   const int dx[] = {-1, 0, 0, 1};   const int dy[] = {0, -1, 1, 0};   inline void init() { ntest = 1; }   int cnt[(int)(1e6 + 5)];   inline void run() {     int n, m, a, b;     cin >> n >> m;     for (int i = 0; i < (m); i++) {       scanf( %d%d , &a, &b);       cnt[a]++;       cnt[b]++;     }     long long x = 0;     for (int i = (1); i <= (n); i++) x += (n - 1 - cnt[i]) * cnt[i];     x /= 2;     cout << (n - 1ll) * n * (n - 2ll) / 6 - x;   }   