#include <stdio.h>
#include <math.h>

//--------------------

FILE * f=fopen ("fractii.in","r");
FILE * g=fopen ("fractii.out","w");

long int n,total,nr,multiplu,ct;
//--------------------
void cit()
{
fscanf (f,"%ld",&n);
}
//--------------------
void tip()
{
fprintf (g,"%ld",total);
}
//--------------------
void calc()
{       total=n;
	for (nr=2;nr<=n;nr++)
	{
		multiplu=2;
		ct=0;
		while (multiplu<=n)
		{
			if ((nr%multiplu==0)||(multiplu%nr==0))
			{
			ct++;
			}
			multiplu++;
		}
		total=total+n-ct;
	}
}
//--------------------
int main()
{
cit();
calc();
tip();
fclose(f);
fclose(g);
return 0;
}
//--------------------