package telerikalpha.workshop.training;

import java.util.Scanner;

public class Homework {
    public static void main(String[] args) {
        Scanner userInpit = new Scanner(System.in);
        int numberN = userInpit.nextInt();
        int counter = 0;

      /*  for(int i = numberN - 1; i >= 1; i--){
            counter++;
            if(numberN % i == 0){
                break;
            }
        }*/

        if (numberN > 1) {
            for (int j = 2; j < numberN; j++) {

                if (numberN % j == 0) {
                    counter = numberN - (numberN / j);
                    break;
                }
            }
        }

        System.out.println(counter);
    }
}