#include<iostream>
#include<iomanip>
#include<math.h>
#include<algorithm>
#include<utility>
#include<queue>
#include<string.h>
#include<string>
#include<set>
#include<map>
#include<vector>
using namespace std;
typedef long long LL;
typedef pair<int, int> P;

int A,P;
int main(){
    cin>>A>>P;
    cout<<(3*A+P)/2;
    return 0;
}