题解 | #完全数计算#

import java.util.Scanner;

// 注意类名必须为 Main, 不要有任何 package xxx 信息
public class Main {
    public static void main(String[] args) {
        Scanner in = new Scanner(System.in);
        int num = in.nextInt();
        in.close();
        if(num < 6){
            System.out.println(0);
            return;
        }

        int count = 0;

        for(int i = 6; i <= num; i++){
            int sum = 0;
            for(int j = 1; j <= i / 2; j++){
                if(i % j == 0){
                    sum += j;   //统计因数的和
                }
            }

            if(sum == i){
                count++;
            }
        }

        System.out.println(count);
    }
}