package infoPb_4;

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

public class Main {
    public static void main(String[] args) {
        try {
            BufferedReader firstLine = new BufferedReader(new FileReader("/home/sebastian.rapa/Projects/InfoArenaProblems/src/infoPb_4/infoPb_4_resource"));

            int gigelNumber = Integer.parseInt(firstLine.readLine());

            BufferedWriter writer = new BufferedWriter(new FileWriter("/home/sebastian.rapa/Projects/InfoArenaProblems/src/infoPb_4/infoPb_4_answer"));
            writer.write(Integer.toString(getIreductableFractions(gigelNumber)));

            writer.close();

        } catch (Exception e) {
            e.printStackTrace();
        }
    }

    private static int getIreductableFractions(int gigelNumber) {

        HashSet<Double> ireductibleFractions = new HashSet<>();

        for (double i = 1; i <= gigelNumber; i++) {
            for (double j = 1; j <= gigelNumber; j++) {
                if (((i % j) > 0) || (j == 1)){
                    ireductibleFractions.add(i/j);
                }
            }
        }

        return ireductibleFractions.size();
    }

}