#include <stdio.h>

int cmmdc(int a,int b)
{
	while (a!=b)
		(a>b)? (a=a-b) : (b=b-a);
	return a;
}
int rezolvare(int n)
{
	int i,j,nr=0;
	nr+=((2*n)-1);
	for (i=2;i<n;i++)
		for (j=i+1;j<=n;j++)
			if (cmmdc(i,j)==1)
				nr+=2;
	return nr;
}

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

	fscanf(f,"%d", &n);

	printf("%d",rezolvare(n));

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