#include <fstream>

using namespace std;
ifstream cin("fractii.in");
ofstream cout("fractii.out");
int cmmdc(int a,int b)
{
    int r=a%b;
    while(r)
    {a=b;
    b=r;
    r=a%b;
    }
    return b;
}
int main()
{
    int n,i,j,s=0;
    cin>>n;
    for(i=1;i<=n;i++)
    {
        for(j=i+1;j<=n;j++)
        {
            if(cmmdc(i,j)==1)
                s=s+2;
        }
    }
    cout<<s+1;
    cin.close();
    cout.close();
    return 0;
}