T = int(input())
def cmp(A,B):
    for i in range(min(len(A),len(B))):
        if A[i] < B[i]:
            return True
    return False
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):
        nY = Y + Y
        if cmp(X,nY):
            print('Y')
        else:
            print('X')
    else:
        if cmp(Y,X + X):
            print('X')
        else:
            print('Y')