func_code_string: #include <bits/stdc++.h>   using namespace std;   const int MaxN = 10004, NA = -1, MaxC = 0x3F3F3F3F;   int m, n, x;   int f(int n, int m, int x) {     n -= x + x;     m -= x + x;     if (n <= 0 || m <= 0) return 0;     return (n * m + 1) >> 1;   }   int main(void) {     while (scanf(  %d %d %d , &n, &m, &x) != EOF) {       printf( %d n , f(n, m, x - 1) - f(n, m, x));     }     return 0;   }   