#include <bits/stdc++.h>
#define IOS ios::sync_with_stdio(0);cin.tie(0);cout.tie(0);
#define fu(i,r,t) for(int i=r;i<=t;i++)
#define fd(i,r,t) for(int i=r;i>=t;i--)
#define Set set<int>
#define int long long
#define P pair<int,int>
const int maxn = 1005;
const int INF = 1e17 +6;
using namespace std;
int n,m,a[maxn],b[maxn],c[maxn];
set<int>T;
int32_t main() {
    IOS;
    cin>>n>>m;
    cout<<(n*3+m)/2);
    return 0;
}
