#include <bits/stdc++.h>
using namespace std;
using ll = long long;
void solve() {
	ll a, b;
	cin >> a >> b;
	if ((a/4ll) <= (b/2ll)) {
		cout << (a/4ll)*3ll << endl;
		return;
	}
	ll count2 = 0ll;
	count2 += (b/2ll);
	a -= count2*4ll;
	b -= count2*2ll;
	count2 += ((a/10ll)*2ll);
	a = (a%10ll);
	if (a > 5ll) {
		count2++;
	}
	cout << count2*3ll << endl;
	return;
}
int main() {
	int a;
	cin >> a;
	while(a--) {
		solve();
	}
}