#include <bits/stdc++.h>
#if __has_include(<cpp-dump/cpp-dump.hpp>)
#include <cpp-dump/cpp-dump.hpp>
#endif
using namespace std;
using ll = int64_t;
#define all(a) a.begin(), a.end()
#define rep(i, s, e) for (ll i = s; i < e; ++i)
#define asort(a) stable_sort(all(a))
#define rsort(a) stable_sort(a.rbegin(), a.rend())
#define sum(a) reduce(all(a))
constexpr double degrees(double a) { return (a * 180.0) / numbers::pi; }
constexpr double radians(double a) { return (a * numbers::pi) / 180.0; }

int main(int, [[maybe_unused]] char* argv[]) {
#ifdef DEBUG
  freopen(argv[1], "r", stdin);
#endif

  ios_base::sync_with_stdio(false);
  cin.tie(0);
  cout << fixed << setprecision(15);

  ll T;
  cin >> T;
  while (T--) {
    ll N, M;
    cin >> N >> M;

    ll ans = 0;
    while (true) {
      if (N >= 4 && M >= 2) {
        ll x = min(N / 4, M / 2);
        N -= x * 4;
        M -= x * 2;
        ans += x * 3;
      } else if (N >= 2) {
        N -= 2;
        M += 4;
      } else {
        println("{}", ans);
        break;
      }
    }
  }
  return 0;
}