N = int(input())
ans = ["0", "1", "2", "3", "4", "5", "6", "7", "8", "9"]

for i in range(N):
    l = list(map(str, input().split()))
    ck = l[4]
    l.pop()
    if ck == "NO":
        for i in range(4):
            try:
                ans.remove(l[i])
            except:
                pass
    else:
        l_ck = ["0", "1", "2", "3", "4", "5", "6", "7", "8", "9"]
        for i in range(4):
            l_ck.remove(l[i])
        for li in l_ck:
            try:
                ans.remove(li)
            except:
                pass

print(ans[0])