import java.io.File;
import java.io.FileNotFoundException;
import java.io.PrintWriter;
import java.util.Scanner;

public class S1 {

	/**
	 * @param args
	 * @throws FileNotFoundException
	 */
	public static void main(String[] args) throws FileNotFoundException {
		// TODO Auto-generated method stub
		Scanner scan = new Scanner(new File("DATA2.txt"));
		PrintWriter pw = new PrintWriter(new File("OUT2.txt"));
		int r = 0;
		while (scan.hasNext()) {
			int n = scan.nextInt();
			if (n == 1) {
				r = 1;
				pw.println(r);
			} else{
				r = constructRects(n);
				pw.println(r);
			}
		}
		scan.close();
		pw.close();
	}

	private static int constructRects(int n) {
		if (n == 2) {
			return 2;
		} else if (n % 2 == 0) {
			return (2 + constructRects(n - 1));
		} else
			return (1 + constructRects(n - 1));
	}

}