#include <bits/stdc++.h>
using namespace std;
using ll = long long;
using vi = vector<int>;
using vvi = vector<vector<int>>;
#define rep(i,n) for(int i = 0; i < (int)(n); i++)
#define erep(i,n) for(int i = 0; i <= (int)(n); i++)
#define all(v) v.begin(), v.end()
#define Yes cout << "Yes" << endl;
#define No cout << "No" << endl;
#define print(n) cout << n << endl;

ll gcd(ll a, ll b){
  if(a%b == 0){
    return b;
  }else{
    return gcd(b, a%b);
  }
}

int main() {
  int T; cin >> T;
  rep(i,T){
  	ll N,M; cin >> N >> M;
  	while(N > 2*M){
  		N -= 2; M += 4;
  	}
  	print((N/4)*3);
  }
}