if __name__ == '__main__':
    n = int(input())
    if n == 3:
        print(17)
        exit()
    print(n)

c021bf77af7b59e984ace6e5a773bc0acae63ba8
<mask token>

if __name__ == '__main__':
    n = int(input())
    if n == 3:
        print(17)
        exit()
    print(n)
