Вывод
-1.0
package com.javarush.task.task05.task0507;
import java.io.BufferedReader;
import java.io.InputStreamReader;
import java.io.InputStream;
import java.io.Reader;
/*
Среднее арифметическое
*/
public class Solution
{
public static void main(String[] args) throws Exception
{
BufferedReader reader = new BufferedReader(new InputStreamReader(System.in));
int y;
int w = 0;
int x = 0;
double a = (x+1.0)/(w-1.0);
while (true)
{
if (x!=(-1))
{
y = Integer.parseInt(reader.readLine());
x += y; //143
w++; //5
}
break;
}
System.out.println(a);
}
}