from math import gcd
import sys
input = sys.stdin.readline

for _ in range(int(input())):
    S = list(input().rstrip())
    T = list(input().rstrip())
    n, m = len(S), len(T)
    lcm = n * m // gcd(n, m)
    ans = -1
    for i in range(lcm):
        if S[i % n] > T[i % m]:
            ans = 'X'
            break
        elif S[i % n] < T[i % m]:
            ans = 'Y'
            break
    if ans == -1:
        if n > m:
            ans = 'X'
        else:
            ans = 'Y'
    print(ans)