#include <iostream>
#include <fstream>
using namespace std;
int v[1000];
long long int n,s=0,rasp;
int main()
{
    ifstream in("fractii.in");
    ofstream out("fractii.out");
    in>>n;
    for(int i=1;i<=n;i++)
        v[i]=i-1;
    for(int i=1;i<=n;i++)
    {
        for(int j=i*2;j<=n;j=j+i)
            v[j]=v[j]-v[i];
    }
    for (int i=1;i<=n;++i)
    {
        s+=v[i];
    }
        s=s*2+1;
        cout<<s;
    return 0;
}