#include <fstream>

using namespace std;

long n;

void read(){
	ifstream file ("fractii.in"); 
	file>>n;
	file.close();
}

int cmmdc(int a,int b){
    if (b==0) return a;
    else return cmmdc(b,a%b);
}

int fractii(){
	int fr=2*n-1;
	for(int i=2;i<=n;i++)
		for(int j=2;j<i;j++)
			if(cmmdc(i,j)==1)fr+=2;	
	return fr;
}

int main(){
	read();
	ofstream file_o ("fractii.out");
	file_o<<fractii();
	file_o.close();
}