n = int(input())
nlist = [input().split() for i in range(n)]
number = ["0", "1", "2", "3", "4", "5", "6", "7", "8", "9"]
no_list = []
yes_list = []
answer = ""

for i in range(n):
    if nlist[i][4] == "NO":
        no_list.append(nlist[i][0])
        no_list.append(nlist[i][1])
        no_list.append(nlist[i][2])
        no_list.append(nlist[i][3])
    else:
        yes_list.append(nlist[i][0])
        yes_list.append(nlist[i][1])
        yes_list.append(nlist[i][2])
        yes_list.append(nlist[i][3])

if not no_list:
    res = [e for e in set(yes_list) if yes_list.count(e) > 1]
    print(res[0])
elif not yes_list:
    diff = set(no_list) ^ set(number)
    answer = list(diff)
    print(answer[0])
else:
    res = [e for e in set(yes_list) if yes_list.count(e) > 1]
    if not res:
        diff = set(no_list) ^ set(number)
        diff2 = set(list(diff)) & set(yes_list)
        answer = list(diff2)
        print(answer[0])
    else:
        diff = set(no_list) ^ set(number)
        diff2 = set(list(diff)) & set(res)
        answer = list(diff2)
        print(answer[0])