#include <stdio.h>
#include <stdlib.h>
int main()
{
    int n,i,j,s=0;
    freopen("fractii.in","r",stdin);
    freopen("fractii.out","w",stdout);
    fscanf(stdin,"%d",&n);
    for(j=1;j<=n;j++)
        s++;
    for(i=2;i<=n;i++)
        s++;
    for(i=2;i<=n;i++)
        for(j=2;j<=n;j++)
    {
        if(i>=j && i%j!=0)
            s++;
        if(j>=i && j%i!=0)
            s++;
    }

    fprintf(stdout,"%d",s);
    fclose(stdin);
    fclose(stdout);

    return 0;
}