N = int(input())
f = []
for i in range(N) :
    a,b,c,d,e = map(str,input().split())
    a = int(a)
    b = int(b)
    c = int(c)
    d = int(d)
    if e == "YES" :
        li = []
        for i in range(10) :
            if i not in [a,b,c,d] :
                li.append(i)
        f.extend(li)
    else :
        li = [a,b,c,d]
        f.extend(li)
f = list(set(f))
for i in range(10) :
    if i not in f :
        print(i)
        break