#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: 1150
	User: wtq001
	Language: C++
	Result: Accepted
	Time:9 ms
	Memory:2072 kb
****************************************************************/