#include<bits/stdc++.h>
#define lowbit(x) (x & (-x))
#define endl "\n"
#define ll long long
#define int long long
#define ull unsigned long long
#define fi first
#define se second
using namespace std;
#define pii pair<int, int>
#define rep(i, a, b) for(int i = a; i <= b; i ++ )
#define pre(i, a, b) for(int i = a; i >= b; i -- )
#define IOS ios::sync_with_stdio(false); cin.tie(0); cout.tie(0);
mt19937_64 rnd(time(0));
const int N = 1e6 + 10;

int n,m;

void solve()
{

    cin>>n>>m;

    if(n==1&&m==1){
        cout<<"6\n";
    }
    else if(n==1){

        int ans=0;
        if(m%4==1)ans=6;
        else if(m%4==2)ans=9;
        else if(m%4==3)ans=10;
        ans+=14*(m/4);
        cout<<ans<<"\n";
    }
    else if(m==1){

        int ans=0;
        if(n%4==1)ans=6;
        else if(n%4==2)ans=8;
        else if(n%4==3)ans=9;
        ans+=14*(n/4);
        cout<<ans<<"\n";

    }
    else{

        int ans=n*m*6;
        cout<<ans<<"\n";

    }
    
}
signed main()
{
    // IOS;
    int _;
    _ = 1;
    // cin >> _;
    // scanf("%d", &_);
    while(_ -- )
    {
        solve();
    }
	return 0;
}