#include <fstream>
using namespace std;
ifstream f("fractii.in");
ofstream g("fractii.out");
int prim(long int i)
{
    for(int d=2;d<=i/d;d++)
        if(i%d==0)
        return 0;
    return 1;
}
int main()
{
    long int n,s;
    f>>n;s=2*n-1;
    for(long int i=2;i<=n;i++)
        for(long int j=2;j<=n;j++)
           if(i!=j)
             {if(i<j)
                {if(prim(i)==1||prim(j)==1)
                if(j%i!=0)
                   s++;
                   }
             else
                {if(prim(i)==1||prim(j)==1)
                if(i%j!=0)
                   s++;}}
     g<<s;


    return 0;
}