func_code_string: #include <bits/stdc++.h>   using namespace std;   int main() {     int N, M;     scanf( %d%d , &N, &M);     long long ans = 0;     for (int b = M + 1; b <= (N + 1) / 2; b++) {       for (int a = M + 1; a <= N - M; a++) {         int coe = (b * 2 - 1 == N ? 3 : 6);         int num = (2 * b - a) * (N + 1 - b);         int den = b + a;         int x = (num - 1) / den;         if (x <= M) break;         x = min(x, N - M);         int tmp = max(x - M, 0);         ans += tmp * coe;       }     }     cout << ans <<   n ;   }   