num = ["0","1","2","3","4","5","6","7","8","9"]
for N in range(int(input())):
	input_line = input().split()
	if input_line[4] == "YES":
		num = set(num)&set(input_line)
		num = list(num)
	else:
		for i in range(4):
			if input_line[i] in num:
				num.remove(input_line[i])
print(num[0])