t = int(input())
for i in range(t):
    x = input()
    y = input()
    lx = len(x)
    ly = len(y)
    f = False
    for j in range(max(lx,ly)):
        if x[j%lx] < y[j%ly]:
            f = True
            print("Y")
            break
        elif x[j%lx] < y[j%ly]:
            f = True
            print("X")
            break
    if f == False:
        if lx < ly:
            print("Y")
        else:
            print("X")