import sys
from collections import Counter

sys.setrecursionlimit(10 ** 6)
int1 = lambda x: int(x) - 1
p2D = lambda x: print(*x, sep="\n")
def MI(): return map(int, sys.stdin.readline().split())
def LI(): return list(map(int, sys.stdin.readline().split()))
def LLI(rows_number): return [LI() for _ in range(rows_number)]

def main():
    ans = [True] * 10
    n = int(input())
    for _ in range(n):
        s = input().split()
        ad = set(map(int, s[:-1]))
        if s[-1] == "YES":
            for i in range(10):
                if i in ad: continue
                ans[i] = False
        else:
            for i in ad:
                ans[i] = False
    for i in range(10):
        if ans[i]:
            print(i)
            break

main()