n = int(input())
l = []
for _ in range(n):
    a,b,c,d,e = input().split()
    a,b,c,d = map(int, [a, b, c, d])
    l.append([a, b, c, d, e])
for i in range(10):
    ok = True
    for a,b,c,d,e in l:
        if e == 'NO' and i in (a, b, c, d):
            ok = False
        if e == 'YES' and i not in (a, b, c, d):
            ok = False
    if ok:
        print(i)
        exit(0)