#define rep(i,n) for(int i=0;i<(int)(n);i++)
#define ALL(v) v.begin(),v.end()
typedef long long ll;
 
#include<bits/stdc++.h>
using namespace std;

int main(){
  ios::sync_with_stdio(false);
  std::cin.tie(nullptr);
  
  int t;
  cin>>t;
  while(t--){
    ll l,r;
    cin>>l>>r;
    
    ll k=r-l;
    ll m=k/4*4;
    if(k%8==0) cout<<2*l+m<<endl;
    else if(k%8<4) cout<<1<<endl;
    else if(k%8==4) cout<<((2*l+m)^1)<<endl;
    else cout<<0<<endl;
  }
  
  return 0;
}