def solve():
    x = input()
    y = input()
    if len(x) == len(y):
        if x < y:
            print('Y')
        else:
            print('X')
    if len(x) > len(y):
        if x[len(y)] >= y[0]:
            print('X')
        else:
            print('Y')
    if len(x) < len(y):
        if y[len(x)] >= x[0]:
            print('Y')
        else:
            print('X')

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