#include <stdio.h>

int v[1000005];
int erast(int n)
{
int i,j;

   for(i=1;i<=n;i++)
   v[i]=i-1;
   {
       for(i=2;i<=n;i++)
       {
           for(j=i+i;j<=n;j+=i)
           {
           v[j]-=v[i];
           }
       }
   }

return v[n];
}



int main()
{

int i, a,b;
FILE *fp;
fp=fopen("fractii.in","r");
fscanf(fp,"%d",&a);
b=0;
for(i=1;i<=a;i++)
{
b+=erast(i);
}
b=b*2+1;
FILE *fw;
fw=fopen("fractii.out","w");
fprintf(fw,"%d",b);
fclose(fp);
fclose(fw);
return 0;
}