#include <iostream>
#include <fstream>
using namespace std;
ifstream fin("fractii.in");
ofstream fout("fractii.out");
int main()
{
    int n,i,j,p,q,i1,nr=0,ok=0,total=0;
fin>>n;
 for(i=2;i<=n;i++){
    for(j=2;j<=n;j++){
    p=i;
    q=j;
    for(i1=2;i1<=p;i1++)if((p%i1==0 && q%i1==0)||(p==q)) ok=1;
    if(ok==1)nr++;
    ok=0;

 }  }
 total=p*q-nr;
 fout<<total;
    return 0;
}