#include<stdio.h>
int main()
{
long n,m,p,q;
FILE *fin,*fout;
fin=fopen("fractii.in","r");
fscanf(fin,"%ld",&n);
m=n;

for (p=1;p<=n;p++)// for (q=1;q<=n;q++)
{q=2;
while(q<=n)
{if(p%2!=0) {if(p%q!=0) {m++;q++;};};
 else {if(p%q!=0) {m++;q=q+2;};};
}
fout=fopen("fractii.out","w");
fprintf(fout,"%ld",m);
fclose(fin);
fclose(fout);
return 0;
}