#include<bits/stdc++.h>
using namespace std;
using i64=long long;
using u64=unsigned long long;
#define ll long long
const int inf=1e9;
const ll inff=1e18;
using i128=__int128;

void solve(){
    int n,m;
    cin>>n>>m;
    int a[]={6,9,10,14};
    int b[]={6,8,9,14};
    if(n==1){
        cout<<m/4*14+a[m%4-1]<<'\n';
        return;
    }
    if(m==1){
        cout<<n/4*14+b[n%4-1]<<'\n';
        return;
    }
    cout<<m*n*6<<'\n';
}

int main(){
    ios::sync_with_stdio(0);cin.tie(0);
    int t=1;
    // cin>>t; 
    while(t--){
        solve();
    }
    return 0;
}