using System;

using System.Collections.Generic;

public class MovingTotal

{

private List<int> nums;

private HashSet<int> finalToal;

​

public MovingTotal()

{

    nums = new List<int>();

    finalTotal = new HashSet<int>();

}

​

public void Appent(int[] list)

{

    foreach(var numbers in nums)

    {

        nums.Add(numbers);

        if(nums.Count > 3)

        {

            int sum = nums[nums.Count-3] + nums[nums.Count-2] + nums[nums.Count-1];

            finalTotal.Add(sum);

        }

    }

}

​

public bool Contains(int total)

{

    return finalTotal.Contains(total);

}

    public static void Main(string[] args)

    {

        MovingTotal movingTotal = new MovingTotal();

        movingTotal.Append

    }

}

​

​