#include<bits/stdc++.h>
using namespace std;
    bool wm(int n){
    bool r=true;
    int s=1;
    for(int i=2;i<=sqrt(n);i++){
        if(n%i==0){
            if(i==n/i) s=s+i;
            else s=s+i+n/i;
        }
    }
    if(s==n) r=true;
    else r=false;
    return r;
}
int main(){
	int n,a=0;
	cin>>n;
	for(int i=2;i<=n;i++){
		if(wm(i)) a++;
	}
	cout<<a; 
	 


	return 0;
}

/**************************************************************
	Problem: 1150
	User: zhuanghaoxiang
	Language: C++
	Result: Accepted
	Time:8 ms
	Memory:2072 kb
****************************************************************/