n = int(input())
ng, ok = [], []
for _ in range(n):
    l = list(input().split())
    for i in range(4):
        if l[-1]=='YES':
            ok.append(l[i])
        else:
            ng.append(l[i])

ret = None
for i in range(10):
    if i not in ng:
        if ok.count(i)==n:
            ret = i
            break
if ret:
    print(ret)
else:
    for i in range(10):
        if i not in ng:
            print(i)