#include<bits/stdc++.h>
using namespace std;
void print(int arr[],int n){
    for(int i=0;i<n;i++){
        cout<<arr[i]<<" ";
    }
    cout<<endl;
}
int main(){
        int n,p;
        cin>>n>>p;
        int pieces=(n*3)+p;
        cout<<pieces/2;
    return 0;
    
}