T = int(input())
X = []
Y = []
for _ in range(T):
    X.append(input())
    Y.append(input())
for i in range(T):
    x = X[i]
    y = Y[i]
    lenx = len(x)
    leny = len(y)
    if lenx>leny:
        v = -(-lenx//leny)
        y = y*v
        y = y[:len(x)]
        if x>=y:
            print('X')
        else:
            print('Y')
    else:
        v = -(-leny//lenx)
        x = x*v
        x = x[:len(y)]
        if y>=x:
            print('Y')
        else:
            print('X')