#include<stdio.h>
#include<conio.h>

int main()
{
clrscr();
long int a,i,j,n,k;
long int v[100];
FILE *f,*g;
f=fopen("Fractii.in","r");
g=fopen("Fractii.out","w");
fscanf(f,"%ld \n",&n);

k=0;
for (i=1;i<=n;i++)
{
for (j=1;j<=i;j++)
{ 
if (i%j!=0) k++;
}
}
k+=n;
k*=2;
k--;
fprintf(g,"%ld",k);
fclose(f);
fclose(g);
return 0;
}