#include <stdio.h>
int fractii(int N)
{
    int q=1,p=1,s=1,t=N;
    if (p/q!=1 && q<=N)
        {
            s++;
            q++;
        if (q=N) {
                    p++;
                    q=1;
                    fractii(N-1);
        }
    else
            q++;
        }

    if (t=0)
        return s;
}
int main()
{FILE *in,*out;int s=1;
int N;
    in=fopen("fractii.in","r");
    out=fopen("fractii.out","w");
    fscanf(in,"%d",&N);
    if (N>=1 && N<=1000000)
        fractii(N);
        fprintf(out,"%d",s);fflush(stdout);
        fclose(in);
        fclose(out);
    return 0;


}