#include<stdio.h>
using namespace std;
#define dim 1000001
#include<math.h>
#include<string.h>
int n,p[dim],i,j,nr,N,P;
long long nrf;

void descompune()
{j=1; nr=0;
while(N>1)
{j++; 
	while(N%j==0)
		{N/=j; 
		if(p[j]==0)
			nr++;
		p[j]++; }

}


}

int main ()
{
 FILE *f=fopen("fractii.in","r"), *g=fopen("fractii.out","w");
	
    fscanf(f,"%d",&n);

for(i=2;i<=n;i++)
{N=i;P=1;
	descompune();
	for(j=2;j<=i;j++)
	{	if(p[j]!=0)
			{
				P*=(j-1)*(long long)pow(j,p[j]-1);
				nr--;
			}
		if(nr==0)
			break;
	}
nrf+=P;
memset(p,0,sizeof(p));
}	


	fprintf(g,"%lld",2*nrf+1);
	
fclose(f);
fclose(g);	
return 0;
}