Start of hex cell

ConsoleApp/Maps/HexCell.cs

@@ -1,7 +1,20 @@
-namespace ConsoleApp
+using System;
+using System.Collections.Generic;
+
+namespace ConsoleApp.Maps
 {
-    public class HexCell
+    public struct HexCell
     {
-        
+        public int Q { get; }
+        public int R { get; }
+        public int S { get; }
+        public HexCell(int q, int r, int s)
+        {
+            if (q + r + s != 0) throw new ArgumentException("q + r + s must be 0");
+            Q = q;
+            R = r;
+            S = s;
+        }
+  
     }
 }