N = int(input())
anslist = []
for i in range(N):
    anslist.append(input().split())

ans_yes = []
ans_no = []

for _ in anslist:
    if _[4] == "YES":
        for k in range(4):
            ans_yes.append(_[k])
    else:
        for k in range(4):
            ans_no.append(_[k])

# s = set()
# ans_yes = [x for x in ans_yes if x in s or s.add(x)]
uq_ans_yes = []
for _ in ans_yes:
    if _ not in uq_ans_yes:
        uq_ans_yes.append(_)
ans_yes = uq_ans_yes

uq_ans_no = []
for _ in ans_no:
    if _ not in uq_ans_no:
        uq_ans_no.append(_)
ans_no = uq_ans_no

# print(ans_yes)
# print(ans_no)
if len(ans_no) == 9:
    for i in range(10):
        if str(i) not in ans_no:
            print(i)
elif len(ans_no) == 0:
    s = set()
    ans_yes = [x for x in ans_yes if x in s or s.add(x)]
    print(ans_yes[0])
else:
    # s = set()
    # ans_yes = [x for x in ans_yes if x in s or s.add(x)]
    for _ in ans_no:
        if _ in ans_yes:
            ans_yes.remove(_)
    # print(ans_yes)
    print(ans_yes[0])