def main():
    n = int(input())
    e = [[i for i in input().split()] for _ in range(n)]
    
    ans = [True] * 10
    
    for ee in e:
        if ee[4] == 'YES':
            b = [False for _ in range(10)]
        else:
            b = [True for _ in range(10)]
        for i in range(4):
            if ee[4] == 'YES':
                b[int(ee[i])] = True
            else:
                b[int(ee[i])] = False
        for i in range(10):
            ans[i] &= b[i]
    print(ans.index(True))
    
if __name__ == '__main__':
    main()