def is_prime(n):
    """
    Return True if n is a prime number, otherwise False

    example:
    is_prime(19)
    # True
    """
    if n < 2:
        return False

    i = 2
    while i * i <= n:
        if n % i == 0:
            return False
        i += 1

    return True

# ===== Provided by the TA. Do not modify. =====
def main() -> None:
    n = int(input())
    print(is_prime(n))


main()