#include<iostream>
#include<vector>
using namespace std;
int main()
{
  int q;
  cin >> q;
  for(;q--;){
    int n,m;
    cin >> n >> m;
    long long left=-1,right=1e9;
    while(left+1!=right){
      long long mokuteki=(left+right)/2;
      if(mokuteki*4<n)left=mokuteki;
      else if(mokuteki*8<n+m)left=mokuteki;
      else right=mokuteki;
    }
    cout << right << endl;
  }
}