prime number or not java program

import java.io.*;
class PrimeNo{
public static void main(String args[]){
int num = Integer.parseInt(args[0]);
int flag=0;
for(int i=2;i<num;i++){
if(num%i==0)
{
System.out.println(num+" is not a Prime Number");
flag = 1;
break;
}
}
if(flag==0)
System.out.println(num+" is a Prime Number");
}
}

OUTPUT