def solve():
    S = input()
    T = input()
    ls = len(S)
    lt = len(T)
    ll = max(ls, lt) * 5
    S *= ((ll + ls - 1) // ls)
    T *= ((ll + lt - 1) // lt)
    S = S[:ll]
    T = T[:ll]
    if S > T:
        print("X")
    elif S < T:
        print("Y")
    elif ls < lt:
        print("Y")
    else:
        print("X")

for _ in range(int(input())):
    solve()