public class Solution {
public static void main(String[] args) throws Exception {
BufferedReader reader =new BufferedReader(new InputStreamReader(System.in));
int num=0;
int sum=0;
double b=0;
while (true) {
String aa=reader.readLine();
int a=Integer.parseInt(aa);
if (a==-1 ) break;
num++;
sum+=a;
b=sum/num;
}
System.out.println(b);
}
}
package com.javarush.task.task05.task0507;
import java.io.BufferedReader;
import java.io.InputStreamReader;
/*
Среднее арифметическое
*/
public class Solution {
public static void main(String[] args) throws Exception {
BufferedReader reader =new BufferedReader(new InputStreamReader(System.in));
int num=0;
int sum=0;
float srarf=0;
while (true) {
String aa=reader.readLine();
int a=Integer.parseInt(aa);
if (a==-1 ) break;
num++;
sum+=a;
srarf=sum/num;
}
System.out.println(srarf);
}
}