import java.util.*;


public class NumberStatistics {

    private int amountOfNumbers;
    private int sumOfNumbers;
    private ArrayList<Integer> list;


    public NumberStatistics(){
     ArrayList<Integer> list = new ArrayList<Integer>();
    }

    public void addNumber(int number){
        this.amountOfNumbers++;
        list.add(number);
    }

    public int amountOfNumbers(){
        return amountOfNumbers;
    }

    public int sum(){
     int sum = 0;
     for(int i : list){
       sum = sum +i;
     }
     return sum;

    }

    public double average(){
      double average = this.sum()/amountOfNumbers;
      return average;
    }












}