题解 | #求平均数#

import java.util.Scanner;

public class Main {

    public static void main(String[] args) {
        Scanner scan = new Scanner(System.in);

        //write your code here......
        
        double avg = 0;
        int count = 0;
        while (true){
            int i = scan.nextInt();
            if (i<0){
                break;
            }
            avg += i;
            count++;
        }
        avg /= count;
        System.out.println(String.format("%.2f",avg));

        //输出格式为：System.out.println(String.format("%.2f",avg));
        

    }
}