题解 | #完全数计算#

import java.util.Scanner;

public class Main {
    public static void main(String[] args) {
        Scanner sc = new Scanner(System.in);
        while (sc.hasNextInt()) {
            int n = sc.nextInt();
            int count = 0;
            for (int i = 2; i <= n; i++) {
                int temp = 0;
                for (int j = 1; j <= (int)Math.sqrt(i); j++) {
                    if (i % j == 0) {
                        if (j * j == i || j == 1) {
                            temp = temp + j;
                        } else {
                            temp = temp + j + i / j;
                        }
                    }
                }
                if (i == temp) {
                    count++;
                }
            }
            System.out.println(count);
        }
    }
}