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