#include<bits/stdc++.h>
using namespace std;
int yzh(int n){
    int s=1;
    for(int i=2;i<n;i++){
        if(n%i==0){
            s+=i;
        }
    }
    return s;
}
int main(){
    int n,c=0;
    cin>>n;
    for(int i=2;i<=n;i++){
        if(yzh(i)==i){
            c++;
        }
    }
    cout<<c<<endl;
}
/**************************************************************
	Problem: 1150
	User: mariooo
	Language: C++
	Result: Accepted
	Time:9 ms
	Memory:2072 kb
****************************************************************/