import java.util.Scanner;
 
public class IsPrime {
    
    static boolean CheckPrime(int NumberPassedIn) {

        boolean IsPrime = true;

        for (int i = 2; i < NumberPassedIn; i = i + 1) {
            if (NumberPassedIn % i == 0) {
                IsPrime = false;
            }
        }
        return IsPrime;
    }

    
    public static void main(String args[])
    {
 
        // Variables
        int NumberInputted;
        
        // Read In
        Scanner input = new Scanner(System.in);
        NumberInputted = input.nextInt();

        // Close Scanner
        input.close();

        if (CheckPrime(NumberInputted) == true)
            System.out.println(NumberInputted + " is a prime.");
        else
            System.out.println(NumberInputted + " is not a prime.");
    }
}