题解 | #完全数计算#

import java.util.Scanner;

/**
找不到什么规律，只能暴力解法！！
 */
public class Main {
    public static void main(String[] args) {
        Scanner in = new Scanner(System.in);
        // 注意 hasNext 和 hasNextLine 的区别
        while (in.hasNextInt()) { // 注意 while 处理多个 case
            int n = in.nextInt();
            int count = 0;
            for(int i = 2; i <= n; i++){
                int sum = 0;
                for(int j = 1; j <= Math.sqrt(i); j++){
                    if(i % j == 0){
                        if(j == 1 || j == i / j){
                            sum += j;
                        }else{
                            sum = sum + j + i / j;
                        }
                       
                    }
                }
                if(sum == i){
                    count++;
                }
            }
            System.out.println(count);
        }
    }
}