#include<stdio.h>
int cm(int a,int b)
{
	while(a!=b)
		if(a>b)
			a-=b;
		else
			b-=a;
	return a;
}
int main()
{
	freopen("fractii.in","r",stdin);
	freopen("fractii.out","w",stdout);
	int i,j,n,nr=0,a[1000000],b[1000000];
	scanf("%d",&n);
	for(i=1;i<=n;i++)
		a[i]=i;
	for(i=1;i<=n;i++)
		b[i]=i;
	for(i=1;i<=n;i++)
		for(j=1;j<=n;j++)
			if(a[i]!=b[j])
				if(cm(a[i],b[j])==1)
					nr++;
	printf("%d\n",nr+1);
 return 0;
}