Prime No.

import java.util.*;
class Prime
{
 public static void main(String args[])
 {  
  int n, i, res;
  boolean flag=true;
  Scanner scan= new Scanner(System.in);
  System.out.println("Please Enter a No.");
  n=scan.nextInt();
  for(i=2;i<=n/2;i++)
  {
   res=n%i;
   if(res==0)
   {
    flag=false;
    break;
   }
  }
  if(flag)
   System.out.println(n + " is Prime Number");
  else
   System.out.println(n + " is not Prime Number");
 }
}

Output: