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

ans_yes_list = []
ans_no_list =[]

for _ in inlist:
    if _[4] == "YES":
        for n in range(4):
            ans_yes_list.append(_[n])
    if _[4] == "NO":
            for n in range(4):
             ans_no_list.append(_[n])

uq_ans_no_list = []
for _ in ans_no_list:
    if _ not in uq_ans_no_list:
        uq_ans_no_list.append(_)

s = set()
uq_ans_yes_list = list(set([x for x in ans_yes_list if x in s or s.add(x)]))

if len(uq_ans_no_list) == 9:
    temp = [str(i) for i in range(10)]
    for _ in uq_ans_no_list:
        temp.remove(str(_))
    print(int(temp[0]))
else:
    for _ in uq_ans_yes_list:
        if _ in uq_ans_no_list:
            uq_ans_yes_list.remove(str(_))
    print(int(uq_ans_yes_list[0]))