func_code_string: #include <bits/stdc++.h>   using namespace std;   int main() {     long long int i, j, k, n, m, r, s;     cin >> n;     if (n % 2 == 0) {       m = n / 2;     } else {       m = n - 1;       m = m / 2 - n;     }     cout << m << endl;   }   