#include <stdio.h>
#include <stdlib.h>

int ciur(int x, int y)
{
	int i=0;
	if(x%2==0&&y%2==0) return 1;
	for(i=3;i<=x;i+=2)
		if(x%i==0&&y%i==0)
			return 1;
	return 0;
}

int main(void)
{
	int i,j,n,k,v[1000001],t;
	memset(v,0,1000001);
	FILE *f,*g;
	f=fopen("fractii.in","r");
	g=fopen("fractii.out","w");
	k=0;
	fscanf(f,"%d",&n);
	for(i=1;i<=n;i++)
	{
		memset(v,0,1000001);
		for(j=1;j<=n;j++)
			{
				if(v[j]) continue;
				if(ciur(i,j)){
					v[j]=1;
					for(t=j;t<=n;t+=j)v[t]=1;
					continue;
				}
				k++;
			}
	}
	fprintf(g,"%d\n",k);
	fclose(f);
	fclose(g);
	return 0;
}