func_code_string: #include <bits/stdc++.h>   using namespace std;   template <class T>   void in(T &x) {     x = 0;     bool f = 0;     char c = getchar();     while (c <  0  || c >  9 ) {       if (c ==  - ) f = 1;       c = getchar();     }     while ( 0  <= c && c <=  9 ) {       x = (x << 3) + (x << 1) + (c ^ 48);       c = getchar();     }     if (f) x = -x;   }   long long n, m;   void print(long long x) {     printf( %lld , x);     exit(0);   }   signed main() {     in(n), in(m);     if (n > m) swap(n, m);     if (n == 1) print(m - m % 6 + max(0ll, (m % 6 - 3) * 2));     if ((n & 1) == 0 && (m & 1) == 0) {       if (n == 2 && m == 2)         print(0);       else         print(n * m);     }     if ((n + m) & 1) {       if (m & 1) swap(n, m);       if (m == 2) {         if (n == 3) print(4);         if (n == 7) print(12);       }       print(n * m);     } else       print(n * m - 1);     return 0;   }   