Giving input in runtime and checked whether it is prime on not prime?

PrimeNumberChecker.java

import java.util.Scanner;
public class PrimeNumberChecker {

	public static void main(String[] args) {
		Scanner s=new Scanner(System.in);
		int a=s.nextInt();
		int i=1;
		int count=0;
		while (a>0) {
			do{
				if(a%i==0){
					count++;
				}
				i++;
			}while(i<=a);
			
			
			if(count==2){
				System.out.println("prime");
			}else {
				System.out.println("not prime");
			}
			a=s.nextInt();
		}
		

	}

}