N = int(input())
ans = [True for _ in range(10)]
yes_cnt = 0
for _ in range(N):
    L = list(map(str,input().split()))
    check = [int(item) for item in L[:-1]]
    Answer = L[-1]
    if Answer == 'NO':
        for item in check:
            ans[int(item)] = False
    elif Answer == 'YES':
        temp_ans = [False for _ in range(10)]
        for item in check:
            if ans[item] == True: 
                temp_ans[item] = True
        ans = temp_ans  
for idx,item in enumerate(ans):
    if item == True:
        print(idx)
        break