/*
 * Main.java
 *
 * Created on 27 Μάρτιος 2008, 3:28 μμ
 *
 * To change this template, choose Tools | Template Manager
 * and open the template in the editor.
 *
 * Sto parathiro dinw enan arithmo
 * Mou emfanizei ton proto arithmo pou
 * einai plisiesteros autou pou edwsa
 */

package protos;
import javax.swing.JOptionPane; 
import java.util.Calendar;

/**
 *
 * @author students
 */
public class Main {
    
    static String input(){
        return JOptionPane.showInputDialog(null, "Give me a number: ");
    }
    
    static void message(String x){
        JOptionPane.showMessageDialog(null, "O  " + x + " einai prwtos arithmos!"); 
    }
    
       static void message1(String x){
        JOptionPane.showMessageDialog(null, "Plisiesteros einai o  " + x + " !"); 
    }
    
    /** Creates a new instance of Main */
    public Main() {
    }
    
    /**
     * @param args the command line arguments
     */
    public static void main(String[] args) {
        // TODO code application logic here
        String in = input();
        int num = Integer.parseInt(in);
        int i, j, flag=0;
        int rem=0, arithmos = 1;
        
        for (i=num;i>1;i--){
            flag = 0;
            for (j=2;j<i;j++){
                rem = i%j;
                if (rem==0){
                    flag = 1;
                    break;
                }                
            }
            if (flag==0){
                arithmos = i;
            }
            if(arithmos!=1){
                break;
            }
        }
        if (arithmos == num){
            message("" + arithmos);
        }
        else{
            message1("" + arithmos);
        }
        System.exit(0);
    }
}