#include<bits/stdc++.h>
using namespace std;

void solve(){
  using ll=long long;
  ll n,m;
  cin>>n>>m;
  ll ans=0;
  auto f=[&](ll k){
    if (k<0) return;
    ll n2=n-2*k,m2=m+4*k;
    if (!(n2>=0&&m2>=0)) return;
    ll p=min(n2/4,m2/2);
    ans=max(ans,p*3);
  };
  f(0);f(n/2);f((n-2*m)/10);f((n-2*m+9)/10);
  cout<<ans<<endl;
}

int main(){
  int t;
  cin>>t;
  while (t--) solve();
}