题解 | #完全数计算#

import java.util.*;

public class Main{
    public static boolean fun(int n){
        int sum = 0;
        for(int i = 1; i <= (int)Math.sqrt(n); i++){
            if(n % i == 0 && i != (n/i)){
                sum += i + n/i;
            }
            else if(n % i == 0 && i == (n/i)){
                sum += i;
            }
        }
        if(sum-n == n){
            return true;
        }
        return false;
    }
    public static void main(String[] args){
        Scanner in = new Scanner(System.in);
        int n = in.nextInt();
        int sum = 0;
        
        for(int i = 1; i <= n; i++){
            if(fun(i)){
               sum++; 
            }
        }
        
        System.out.print(sum);
    }
}