#include <cassert>
#include <cmath>
#include <algorithm>
#include <iostream>
#include <iomanip>
#include <climits>
#include <map>
#include <queue>
#include <set>
#include <cstring>
#include <vector>

using namespace std;
typedef long long ll;

void solver(string x, string y) {
  string s1 = x + y;
  string s2 = y + x;

  if (s1 > s2) {
    cout << "X" << endl;
  } else if (s1 < s2) {
    cout << "Y" << endl;
  } else {
    if (x.size() > y.size()) {
      cout << "X" << endl;
    } else {
      cout << "Y" << endl;
    }
  }
}

int main() {
  int T;
  cin >> T;

  for (int i = 0; i < T; ++i) {
    string x;
    string y;
    cin >> x;
    cin >> y;

    solver(x, y);
  }

  return 0;
}