// package org.alex.learn;

import java.io.*;
import java.util.Set;
import java.util.HashSet;;
import java.util.Scanner;

public class Main 
{
    public static void main( String[] args )
    {
        Set<Double> same = new HashSet<>();
        Scanner fileScanner = new Scanner(new FileInputStream("fractii.in"));
        PrintWriter fileOutputPrinter = new PrintWriter("fractii.out");

        int a = fileScanner.nextInt();

        for (int i = 0; i < a; i++) {
            for (int j = 0; j < a; j++) {
                same.add(i/j);
            }
        }

        fileOutputPrinter.println(same.size());


        fileScanner.close();
        fileOutputPrinter.close();
    }
}