#include <iostream>
#include <cmath>

using namespace std;
int yinzihe(int n){
	int i,s=1;
	for(i=2;i<=sqrt(n);i++){
		if(n%i==0){
			s+=i;
			s+=n/i;
		}
	}
	return s;
}
int main(){
	int i,n,c=0;
	cin>>n;
	for(i=2;i<=n;i++){
		if(yinzihe(i)==i){
			c++;
		}
	}
	cout<<c<<endl;
}
/**************************************************************
	Problem: 1150
	User: admin
	Language: C++
	Result: Accepted
	Time:8 ms
	Memory:2072 kb
****************************************************************/