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 sum=0;
        int count=0;
        while(true)
        {
            int input=scan.nextInt();
            if(input<0)
                break;
            sum+=input;//统计和
            count++;//计数
        }
        System.out.println(String.format("%.2f",sum/count));

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

    }
}