#include<stdio.h>


int prim(long int a, long int b)
{
    if (a==b) goto x;
	do
	{
		if (a>b) a=a-b; else if (b>a) b=b-a;
	}
	while(a!=b);
x:	if (a==1) return 1; else return 0;
}

int main()
{
	FILE *in=fopen("fractii.in","r"),
		 *out=fopen("fractii.out","w");
	long int n,i,j,s,comp;
	fscanf(in,"%ld",&n);
	comp=0;
	s=n*2-1;
	for (i=2;i<=n-1;i++)
	{
		for (j=i+1;j<=n;j++) 

		{
			comp++;
			if (prim(i,j)==1) s=s+2;
		
		}
	}
	fprintf(out,"%ld",s);

	return 0;

}