#include <fstream>

using namespace std;

int n;

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

int cmmdc(int a,int b){
	while(a!=b)
		if (a>b) a-=b;
		else b-=a;
	return (a==1)?0:a;
}

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)==0)fr+=2;	
	return fr;
}

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