# -*- coding:utf-8 -*-

if __name__ == "__main__":
	s = raw_input()
	if s == "oda":
		t = "yukiko"
	else:
		t = "oda"
	ans = 0
	for i in xrange(8):
		board = raw_input()
		ans += board.count("w") + board.count("b")
	if ans %2 == 0:
		print s
	else:
		print t