func_code_string: #include <bits/stdc++.h>   int n, m;   long long ans;   int main() {     int i, j, k;     scanf( %d%d , &n, &m);     for (i = m + 1; (i << 1) <= n; ++i) {       k = n - m;       for (j = m + 1; j <= n - m; ++j) {         while (k > m && 0 <= (i << 1) * ((i << 1) - j - ((n << 1) - k + 2)) +                                  3 * j * k + j * ((n << 1) - k + 2))           --k;         ans += k - m;       }     }     ans <<= 1;     if (n & 1) {       i = (n >> 1) + 1;       k = n - m;       for (j = m + 1; j <= n - m; ++j) {         while (k > m && 0 <= (i << 1) * ((i << 1) - j - ((n << 1) - k + 2)) +                                  3 * j * k + j * ((n << 1) - k + 2))           --k;         ans += k - m;       }     }     printf( %I64d n , ans * 3);     return 0;   }   