#include <bits/stdc++.h>
using namespace std;
int main(){
  int T;
  cin >> T;
  for (int i = 0; i < T; i++){
    string x;
    cin >> x;
    string y;
    cin >> y;
    if (x + y > y + x){
      cout << "X" << endl;
    } else if (x + y < y + x){
      cout << "Y" << endl;
    } else if (x > y){
      cout << "X" << endl;
    } else {
      cout << "Y" << endl;
    }
  }
}