#include <stdio.h>

long n,a,b,io,k;
int ok;
float v[1000000],r;

main()
{
        freopen ("fractii.in","r",stdin);
        freopen ("fractii.out","w",stdout);
        k=1;
        scanf("%d",&n);
        for (a=1;a<=n;a++)
        {
            for (b=n;b>=1;b--)
            {
                r=(float)a/b;
                ok=1;
                for (io=1;io<=k;io++)
                    if (r==v[io]) {ok=0;break;}
                if (ok==1)
                {
                    v[k]=r;
                    k++;
                }
            }
        }
        k--;
        printf("%d",k);
        return 0;
}