#include <stdio.h>
int n,r,k,i,j,e,d,m,x,i1,a[100],l;
int main()
{
    freopen("fractii.in","r",stdin);
    freopen("fractii.out","w",stdout);
    scanf("%d",&n);
    k=n;
    for(i=2;i<=n;i++)
    {
		     i1=i;
		     j=2;
		     d=1;
		     l=0;
		     x=0;
		     while(i1>1)
		     {
				e=0;
				if(i1%j==0)
				{
					l++;
					a[l]=j;
				}
				while(i1%j==0)
				 {
					      i1=i1/j;
					     
				 }
				j++;
		     }
	for(j=1;j<=l;j++)
		x=x+n/a[j];
	k=k+(n-x);

    }
    printf("%d",k);
    return 0;
}