Invalid token in class const C#
<p>I know this question has asked here before but I am unable to find what is wrong with my code.</p>

<pre><code>      class Slider
     {
        public int const DEFAULT_SIZE = 20; // Problem is here. Invalid token in class 

    private int rise { get; set; }
    private int run { get; set; }
    private int size { get; set; }

    int positionX = 0;
    int positionY = 0;

    private int leftBoundX { get; set;}
    private int leftBoundY { get; set; }

    private int rightBoundX { get; set; }
    private int rightBoundY { get; set; }

    // Constructor
    Slider()
    {
        size = DEFAULT_SIZE; 
    }

    private void Bound()
    {
        if (positionX &gt; leftBoundX)
            positionX = rightBoundX;
        else if (positionY &gt; leftBoundY)
            positionY = rightBoundY;
        else if (positionX &gt; leftBoundX)
            positionX = rightBoundX;
        else if (positionX &gt; leftBoundX)
            positionX = rightBoundX;
        }
</code></pre>

<p>I googled stuff, they told me to include System.Collection and I did but still same error</p>
