num = int(input())

if num <= 1:
    print(num,"is not a prime number")

if num == 2:
    print(num,"is a prime number")

if num % 2 == 0:
    print(num,"is not a prime number")

else :
    is_prime = True
    for i in range(3, int(num**0.5)+ 1, 2):
      if num % i== 0:
        is_prime = False
        break

    if is_prime:
      print(num, "is a prime number" )

    else:
       print(num, "is not a prime number")