import sys
input = sys.stdin.readline

T=int(input())
for tests in range(T):
    x=input().strip()
    y=input().strip()

    for i in range(max(len(x)*2,len(y)*2)):
        if x[i%len(x)]>y[i%len(y)]:
            print("X")
            break
        elif x[i%len(x)]<y[i%len(y)]:
            print("Y")
            break

    else:
        if len(x)>len(y):
            print("X")
        else:
            print("Y")