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 > 3) {       cout << ((n * m / 2) * 2);     } else {       if (n == 3) {         cout << m * n / 2 * 2;         return 0;       } else {         if (n == 2) {           if (m == 2) {             cout << 0;             return 0;           }           if (m == 3) {             cout << 4;             return 0;           }           if (m == 7) {             cout << 12;             return 0;           }           cout << n * m;         } else {           long long x = m % 6;           long long c = m / 6 * 6;           if (x == 4) {             c += 2;           }           if (x == 5) {             c += 4;           }           cout << c;           return 0;         }       }     }     return 0;   }   