#include <stdio.h>

int cmmdc(int a,int b)
{	
	while (a!=b)
	{
		if (a>b)
			a=a-b; 
		else
			b=b-a;
	}
	return a;
}

int rezolvare(int n)
{
	int i,j,nra,nr=0;

	nr+=((2*n)-1); // 1/x si x/1
	
	for (i=2;i<n;i++)
	{
		nra=0;
		
		for (j=i+1;j<=n;j++)
			if (cmmdc(i,j)==1)
				nra++;
		nr+=(nra*2);
	}
		
	return nr;
}

int main()
{
	int n;

	FILE* f=fopen("fractii.in", "rt");
	FILE* g=fopen("fractii.out", "wt");

	fscanf(f,"%d", &n);
	fprintf(g,"%d",rezolvare(n));

	fclose(f);
	fclose(g);
	
	return 0;
}