from math import gcd
def solve():
  x=input()
  y=input()
  n = len(x)
  m = len(y)
  if x + y == y + x:
    if n > m:
      print('X')
    else:
      print('Y')
    return
  lcm = n * m // gcd(n, m)
  x *= lcm
  y *= lcm
  if x > y:
    print('X')
  else:
    print('Y')



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