from collections import Counter
n = int(input())
yes = []
no = []
y_flag = 0
n_flag = 0
for i in range(n):
	a = input().split()
	if a[-1] == 'YES':
		yes.extend(a[:-1])
		y_flag += 1
	else:
		no.extend(a[:-1])
		n_flag += 1
c = Counter(yes)
if y_flag == 0:
	print(''.join([str(i) for i in range(0, 10) if str(i) not in no]))
elif n_flag == 0:
	print(c.most_common(1))
else:
	if y_flag > 1: yes = [i for i in set(yes) if yes.count(i) > 1]
	for i in range(len(yes)):
		if yes[i] not in no:
			print(yes[i])
			exit()