#include<bits/stdc++.h>
#define int long long
#define  FastIO ios_base::sync_with_stdio(0),cin.tie(0),cout.tie(0)
using namespace std;
int32_t main()
{
    FastIO;
    int a,p;
    cin>>a>>p;
    cout<<(a*3+p)/2;
    }
}