func_code_string: #include <bits/stdc++.h>   int n, m;   int main() {     long long ans;     int b, c, A, B, C, l;     scanf( %d%d , &n, &m);     n++;     m++;     ans = 0;     for (c = m; c <= n - m; c++) {       C = 2 * (n * n - n * c + c * c);       for (b = n - m; b >= m; b--) {         A = 2 * n - b - c;         B = b * (n + c);         l = (C - B) / A;         if (m > l) l = m - 1;         if (l >= n - m) break;         ans += n - m - l;       }     }     printf( %I64d n , ans * 3);     return 0;   }   