public class Solution { public static void main(String[] args) throws Exception { //напишите тут ваш код BufferedReader reader = new BufferedReader(new InputStreamReader(System.in)); double count = 0; double sum = 0; double number = 0; while (true) { number = Double.parseDouble(reader.readLine()); if (number == -1) { break; } count++; sum += number; } System.out.printf("%.1f%n", sum / count); } }