#include<iostream>
#include<stdio.h>
int euclid(int a,int b){
	if(b==0)return a;
	euclid(b,a%b);
}

int n;
int main(){
	freopen("fractii.in", "r", stdin);
	freopen("fractii.out", "w", stdout);
	scanf("%d",&n);
	int x;
	x=n+n-1;
	for(int i=2;i<=n;i++){
		for(int j=i+1;j<=n;j++){
			if(euclid(i,j)==1){
				x+=2;
			}
		}
		
	}
	printf("%d",x);
}