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

class Auxiliar{

	public boolean divizibil(int a,int b){
        int aux=0;
		
        if(a<b){
            aux=a;
            a=b;
            b=aux;
        }
         
        while(b>0){
            aux=a;
            a=b;
            b=aux%a;
        }
        if(a==1){
        	return false;
        }
        return true;
	}
}

public class Main {

	public static void main(String[] args) {
		// TODO Auto-generated method stub
		try {
			Scanner s = new Scanner(new FileInputStream("fractii.in"));
			PrintWriter pw = new PrintWriter("fractii.out");
			int n,i,j,suma = 0;
			Auxiliar a = new Auxiliar();
			
			n = s.nextInt();
			for(i=2;i<=n;i++){
				for(j=2;j<i;j++){
					if(!a.divizibil(i,j)){
						suma=suma+2;
						//System.out.println(suma);
					}
				}
			}
			suma=suma+1+(n-1)*2;
			
			pw.println(suma);

			
			s.close();
			pw.close();
			
			
		} catch (FileNotFoundException e) {
			// TODO Auto-generated catch block
			e.printStackTrace();
		}
	}
}