#include<bits/stdc++.h>
using namespace std;
int n,m;
int main(){
//    freopen("in.txt","r",stdin);
//    freopen("out.txt","w",stdout);
    ios::sync_with_stdio(0),cin.tie(0),cout.tie(0);

    cin>>n>>m;
    if(n==1){
        int t=m/4;
        int k=m%4;
        switch(k){
            case 0:cout<<t*14;break;
            case 1:cout<<t*14+6;break;
            case 2:cout<<t*14+9;break;
            case 3:cout<<t*14+10;break;
        }
        return 0;
    }
    if(m==1){
        int t=n/4;
        int k=n%4;
        switch(k){
            case 0:cout<<t*14;break;
            case 1:cout<<t*14+6;break;
            case 2:cout<<t*14+8;break;
            case 3:cout<<t*14+9;break;
        }
        return 0;
    }
    cout<<6*n*m;
}