#include <iostream>
using namespace std;
#include <cmath>
int main() {
    int num;
    cin >> num;
    int cnt = 0;
    for(int i =2; i<=num;i++){
        int x = 0;
        for(int j = 1; j <= i/2; j++){
            if(i%j == 0){
                x = x + j;
            }
        }
        if(i==x){
            cnt++;
        }
    }
    cout << cnt << endl;
}

暴力解法