def f(x, y, s, t):
    if x == y:
        if len(s) < len(t):
            return 'Y'
        else:
            return 'X'
    if x > y:
        return 'X'
    return 'Y'


T = int(input())
for _ in range(T):
    s = input()
    t = input()
    X = s + t; Y = t + s
    ans = f(X, Y, s, t)
    print(ans)