for _ in range(int(input())):
    x = list(input())
    y = list(input())
    nx = len(x)
    ny = len(y)
    def aaa(x,y):
        ny = len(y)
        nx = len(x)
        for i in range(nx):
            x.append(x[i])
        while len(y) < len(x):
            for i in range(ny):
                y.append(y[i])
    if len(x) > len(y):aaa(x,y)
    elif len(y) > len(x):aaa(y,x)
    n = min(len(x),len(y))
    cnt = 0
    for i in range(n):
        cnt += x[i] == y[i]
    if cnt != n:
        if x > y:
            print("X")
        elif x < y:
            print("Y")
    else:
        if nx > ny:
            print("X")
        else:
            print("Y")
#     print(x,y)