1554C - Mikasa - CodeForces Solution

//ॐ नमः शिवाय
#include<bits/stdc++.h>
#define int long long
using namespace std;
signed main(){
std::ios_base ::sync_with_stdio(false);
std::cin.tie(NULL);
std::cout.tie(NULL);
int T;
//T=1;
std::cin>>T;
for (int i1 = 1; i1 <= T;i1++)
{
    int n,m;
    cin>>n>>m;
    m+=1;
    int ans=0;
    for(int i=32;i>=0;i--){
        int bit1=n&(1LL<<i),bit2=m&(1LL<<i);
        if(bit1 && !bit2){
            break;
        }
        else if(!bit1 && bit2){
            ans+=(1LL<<i);
        }
    }
    cout<<ans<<endl;
}
    return 0;
}