def main():
    numbers = set(map(str, range(10)))
    for _ in range(int(input())):
        A, B, C, D, R = input().split()
        match R:
            case "YES":
                numbers = numbers & {A, B, C, D}
            case "NO":
                numbers = numbers - {A, B, C, D}

    assert len(numbers) == 1
    print(numbers.pop())


if __name__ == "__main__":
    main()