#include<stdio.h>
int p[20],s,n,v[20],x[10];
void rd()
{
FILE *in;
in=fopen("fractii.in","r");
fscanf(in,"%d",&n);
fclose(in);
}
void fr()
{
int q=0;
for(int i=2;i<=n;++i)
       //	if(p[i]==0)
		{
	     //	nr++;
		for(int j=i+i;j<=n;j+=i)
			{
		       //	p[j]=1;
			v[j]--;
			v[i]--;
			x[q]=j;

			q++;
			//s-=2;
			}
	    /*	for(int f=0;f<q;++f)
			if()
			v[x[f]]-=(q-1);
		q=0;*/
		}
}
void dw()
{
FILE *out;
out=fopen("fractii.out","w");
fprintf(out,"%d",s);
fclose(out);
}
int main()
{
rd();
s=0;
v[1]=n;
int i;
for( i=2;i<=n;++i)
	v[i]=n-1;
fr();
for(i=1;i<=n;i++)
	s+=v[i];
//printf(" %d",s);
dw();
return 0;
}