func_code_string: #include <bits/stdc++.h>   using namespace std;   int main() {     long long n, m;     cin >> n >> m;     if (n > m) swap(n, m);     if (n == 2) {       if (m % 4 == 0)         cout << m;       else if (m % 4 == 1)         cout << m + 1;       else         cout << (m / 4) * 4 + 4;     } else if ((m < 2) || (n < 2) || ((m == 2) && (n == 2)))       cout << n * m << endl;     else       cout << (n * m + 1) / 2;     return 0;   }   