#include <fstream>

using namespace std;

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

int n,i,j,nr;

bool primeintreele(int a, int b){
    int r;
    r=a%b;
    while(r){
        a=b;
        b=r;
        r=a%b;
    }
    if(b==1)
        return 0;
    return 1;
}

int main(){
    f>>n;
    for(i=1; i<=n; i++)
    for(j=i+1; j<=n; j++){
        if(!primeintreele(i, j))
            nr++;//g<<i<<" "<<j<<"\n";
    }
    nr*=2;
    nr++;
 g<<nr;

return 0;}