import java.util.Scanner; public class Main { @SuppressWarnings("resource") public static void main(String args[]) { Scanner scanner = new Scanner(System.in); long n=scanner.nextLong(); for(int i=3;i<=Math.sqrt(n);i+=2) { if(n%i==0) { System.out.println(i); return; } } System.out.println(n%2==0?n/2:n); } }