#include<stdio.h>
int main(){
	int n,s=0,d,v[1000],i,x,j,k,m,p;
	freopen("fractii.in","r",stdin);
	freopen("fractii.out","w",stdout);
	scanf("%d",&n);
	for(i=1;i<=n;i++)
		for(j=i;j<=n;j++){
			k=1;
			d=2;
			x=j;
			while(x){
				if(x%d==0){
					v[k]=d;
					k++;
				}
				d++;
				x=x/d;
			}
			p=0;
			for(m=1;m<=k/2;m++)
				if(i>v[m] && i%v[m]==0)
					p=1;
			if(p==0)
				s++;
	}
	s++;
	printf("%d\n",s);	
	fclose(stdin);
	fclose(stdout);
	return 0;
}