#define _USE_MATH_DEFINES
#include<bits/stdc++.h>
#define int long long
#define rep(i,n) for(int i=0;i<n;i++)
#define Rep(i,a,b) for(int i=0;i<b;i++)
#define REP(i,a,b) for(int i=0;i<=b;i++)
#define rev(i,n) for(int i=n-1;i>=0;i--)
#define vi vector<int>
#define vvi vector<vi>
#define pb push_back
#define pi pair<int,int>
#define vp vector<pair<int,int>>
#define mp make_pair
#define all(v) (v).begin(),(v).end()
#define fi first
#define se second
#define MEMSET(a) memset(a,0,sizeof(a))
#define inf (1ll<<60)
#define Yes(f) cout <<(f?"Yes":"No")<<endl//fが真の場合Yesを出力、偽の場合Noを出力
#define yes(f) cout <<(f?"yes":"no")<<endl
#define YES(f) cout <<(f?"YES":"NO")<<endl
#define SORT(v) sort(all(v))
#define RSORT(v) sort(all(v),greater<int>())

using namespace std;

const int mod=1e9+7;

signed main(){
    int a,p;
    cin >> a >> p;
    int p+=a*3;
    cout << p/2 << endl;
}
