func_code_string: #include <bits/stdc++.h>   using namespace std;   int main() {     int n;     cin >> n;     if (n % 2 == 1) {       cout << 0;       return 0;     }     n = n / 2;     if (n % 2 == 0)       cout << n / 2 - 1;     else       cout << n / 2;     return 0;   }   