#include <fstream>

using namespace std;

ifstream in ("fractii.in");
ofstream out ("fractii.out");

int prime (int a, int b) {
    int i,t=0;
    if (a==b)
        t=0;
    else {
        for (i=1; i<=min(a,b); i++) {
            if (a%i==0 && b%i==0)
            t++;
            if (t>2)
                break;
            }

    }
    return t;
}

int main()
{
    int a[1000000],b[1000000],n,f=1,k,l;
    in>>n;
    for (k=1; k<=n; k++){
        a[k]=k;
        b[k]=k;}
    for (k=1; k<=n; k++) {
        for (l=1; l<=n; l++){
            if (prime(a[k],b[l])==1)
            f++;
            }
        }
    out<<f;


    return 0;
}