T = int(input())
def cmp(A,B):#len(A) > len(B)
    for i in range(len(A)*2):
        if A[i%len(A)] > B[i % len(B)]:
            return 1
        elif A[i%len(A)] < B[i%len(B)]:
            return -1
    return 1

for _ in range(T):
    X = list(input())
    Y = list(input())
    if len(X) == len(Y):
        if X > Y:
            print('X')
        else:
            print('Y')
    elif len(X) > len(Y):
        if cmp(X,Y) == 1:
            print('X')
        else:print('Y')
    else:
        if cmp(Y,X) == 1:
            print('Y')
        else:
            print('X')