tracks/csharp/exercises/difference-of-squares/Example.cs in trackler-2.0.8.14 vs tracks/csharp/exercises/difference-of-squares/Example.cs in trackler-2.0.8.15

@@ -1,35 +1,23 @@
 using System;
 using System.Linq;
 
-public class Squares
+public static class Squares
 {
-    private readonly int max;
-
-    public Squares(int max)
+    public static int SquareOfSums(int max)
     {
-        if (max < 0)
-        {
-            throw new ArgumentOutOfRangeException("Max must be positive", "max");
-        }
-
-        this.max = max;
-    }
-
-    public int SquareOfSums()
-    {
         var numbers = Enumerable.Range(1, max);
         int sum = numbers.Sum();
         return sum * sum;
     }
 
-    public int SumOfSquares()
+    public static int SumOfSquares(int max)
     {
         var numbers = Enumerable.Range(1, max);
         return numbers.Select(x => x * x).Sum();
     }
 
-    public int DifferenceOfSquares()
+    public static int DifferenceOfSquares(int max)
     {
-        return SquareOfSums() - SumOfSquares();
+        return SquareOfSums(max) - SumOfSquares(max);
     }
 }
\ No newline at end of file