local n = io.read("*n", "*l")
for i = 1, n do
  local x = io.read()
  local y = io.read()
  local xy = x..y
  local yx = y..x
  if xy < yx then
    print "Y"
  elseif yx < xy then
    print "X"
  else
    print(#x < #y and "Y" or "X")
  end
end