#include<cstdio>
using namespace std;
void sterge(long long v[], long long i,long long &n)
{
long long j;
for(j=i;j<n;j++)
	v[j]=v[j+1];
n--;
}
int main ()
{
freopen("fractii.in","r",stdin);
freopen("fractii.out","w",stdout);
long long n,v[100000],i,j,r,rn;
scanf("%lld ",&n);
rn=r=n;
for(i=1;i<=n;v[i]=i,i++);

for(i=2;i<=n;i++)
	for(j=i+1;j<=n;j++)
		if(v[j]%v[i]==0) {sterge(v,j,n);j--;}
r=r*r;
for(i=2;i<=n;i++)
{
	r-=((rn/v[i])*(rn/v[i]));
}
if(rn%10==0) r+=2;
printf("%lld ",r);
return 0;
}