#include<iostream.h>
#include<fstream.h>
ifstream f1("fractii.in");
ofstream f2("fractii.out");
void main(){
unsigned int k;
long i,j,n;
f1>>n;k=0;
for(i=1;i<=n;i++){
k++;
for(j=2;j<=i;j++){
if(i%j!=0)k++;} }
f2<<k;
}