#include <iostream>
#include <cstdio>
#include <cstring>
#include <vector>
using namespace std;

int a, p;

void in() {
	scanf("%d%d", &a, &p);
}

void solve() {
	int x = p + a*3;
	cout << x/2;
}

int main() {
	in();
	solve();
	return 0;
}
