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

int main() {
      
      
      int t;
      cin>>t;
      while(t--){
          
          int a,b,requiredMul=0,requiredAdd=0;
          cin>>a>>b;
          int diff=b-a;
          
          requiredMul=diff/2;
          requiredAdd=b-(a*pow(2,requiredMul));
          
          
          
          cout<<requiredMul+requiredAdd<<endl;
          
          requiredMul=0;
          requiredAdd=0;
          
          
      }

}