暴力破解

import java.util.Scanner;
/**
 * 【完全数计算】
 *
 */
public class Main {
    public static void main(String[] args) {
        Scanner sc = new Scanner(System.in);
        int nextInt = sc.nextInt();

        int count = 0;
        for (int i = 1; i <= nextInt; i++) {
            if (isPerfectNumber(i)) {
                count++;
            }
        }
        System.out.println(count);
    }

    /**
     * 是否为完全数
     *
     * @param number
     * @return
     */
    public static boolean isPerfectNumber(int number) {
        int num = 0;
        for (int i = 1; i <= number / 2; i++) {
            if (number % i == 0) {
                num = num + i;
            }
        }
        return num == number;
    }
}