#include<stdio.h>
int prime(int &x,int &y){
	int i;
	for(i=2;i<=x;i++)
		if((x%i==0)&&(y%i==0))
			return 0;
	return 1;
}
int main(){
	int N,i,j,k=0;
	freopen("fractii.in","r",stdin);
	freopen("fractii.out","w",stdout);
	scanf("%d",&N);
	k=2*N-1;
	for(i=2;i<=N;i++)
		for(j=2;j<=N;j++)
			if(prime(i,j))
				k++;
	printf("%d",k);
	fclose(stdin);
	fclose(stdout);
	return 0;
}