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