#include<iostream>
#include<fstream>

using namespace std;

int lnko(int a, int b){
    int c=a%b;
    while(c){
        a=b;
        b=c;
        c=a%b;
    }
    return b;
}

int main(){
    int n,t;
    fstream be,ki;
    be.open("fractii.in",ios::in);
    be>>n;
    t=2*n-1;
    be.close();
    for(int i=2;i<=n;i++)
        for(int j=i+1;j<=n;j++)
            if(lnko(j,i)==1) t+=2;
    ki.open("fractii.out",ios::out);
    ki<<t;
    ki.close();
    return 0;
}