#include<bits/stdc++.h>
using namespace std;
int s(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,x=0;
  	cin>>n;
  	for(i=2;i<=n;i++)
    	if(s(i)==i) x++;
  	cout<<x<<endl;
	return 0;
}
/**************************************************************
	Problem: 1143
	User: hongjiaming
	Language: C++
	Result: Wrong Answer
****************************************************************/