import java.io.ObjectInputStream.GetField;
import java.net.NetworkInterface;
import java.util.*;
import java.util.zip.Inflater;

import javax.swing.plaf.synth.SynthSpinnerUI;


public class Main {
	static long gcd(long N, long N2){
		if(N2==0) return N;
		else return gcd(N2, N%N2);
	}
	public static void main(String[] args) {
		Scanner sc = new Scanner(System.in);
		long N = sc.nextLong();
		
		System.out.println(gcd(N,N*(N-1)/2));
	}	
}