#include<bits/stdc++.h>
#define int long long
#define double long double
#define x first
#define y second
using namespace std;
typedef long long LL;
typedef long long ll;
typedef pair<int,int> PII;
const int N=3e5+10;
const int M=1e3+10;
int mod=1e9+7;
int a[N];

void solve(){
    int n,m;cin>>n>>m;
    if(n>1&&m>1) cout<<n*m*6<<"\n";
    else{
        if(n==1){
            int sp=m/4*14;
            if(m%4==1) sp+=3;
            else if(m%4==2) sp+=4;
            else if(m%4==3) sp+=8;
            cout<<sp<<"\n";
        }else{
            int sp=m/4*14;
            if(m%4==1) sp+=2;
            else if(m%4==2) sp+=1;
            else if(m%4==3) sp+=8;
            cout<<sp<<"\n";
        }
    }
}

signed main(){
    ios::sync_with_stdio(false);
    cin.tie(nullptr),cout.tie(nullptr);
    int _;
    _=1;
    // cin>>_;
    while(_--){
        solve();
    }
}