#include <bits/stdc++.h>   using namespace std;   int solve(int n, int m, int k) {     if (n > m) return 0;     if (n == 0) return min(m + 1, (1 << (k + 1)));     if ((1 << k) & n) {       int c = solve(n - (1 << k), m - (1 << k), k - 1);       if (c == (1 << k))         return (1 << (k + 1));       else         return c;     } else {       int z = solve(n, m - (1 << k), k - 1);       if (z == (1 << k))         return 2 * z;       else {         int c = solve(n, m, k - 1);         if (c == (1 << k))           return (1 << k) + z;         else           return c;       }     }   }   void solve() {     int n, m;     cin >> n >> m;     cout << solve(n, m, 29) <<   n ;   }   signed main() {     ios_base::sync_with_stdio(0);     cin.tie(0);     int t;     cin >> t;     while (t--) solve();   }   