Prime Numbers in java

 import java.util.Scanner;

public class Program

{

    public static void main(String[] args) {

        int number;

        Scanner scan = new Scanner(System.in);

        number = scan.nextInt();

        if(number==1||number==2||number==3){

            System.out.println("A prime number");

        }

else if(number%2==0||number%3==0){

    System.out.println("not a prime number");

}

else{

    System.out.println("A prime number");

}

    }

}