diff --git a/IDAstar.cs b/IDAstar.cs
index f3550ab..b52aeca 100644
--- a/IDAstar.cs
+++ b/IDAstar.cs
@@ -1,3 +1,77 @@
+using System.Collections.ObjectModel;
+using System.Threading.Channels;
+
+namespace IdaStar {
+
+    public enum CellState {
+        EMPTY,
+        OBSTACLE,
+        START,
+        DESTINATION,
+        PATH,
+    }
+
+    public static class CellStateUtil {
+        public static CellState FromInput(this char c) => c switch
+        {
+            '#' => CellState.OBSTACLE,
+            ' ' => CellState.EMPTY,
+            'S' => CellState.START,
+            'F' => CellState.DESTINATION,
+            'P' => CellState.PATH,
+            _ => throw new NotImplementedException(),
+        };
+
+		public static char ToInput(this CellState state) => state switch
+		{
+			CellState.EMPTY => ' ',
+			CellState.OBSTACLE => '#',
+			CellState.START => 'S',
+			CellState.DESTINATION => 'F',
+            CellState.PATH => 'P',
+			_ => throw new NotImplementedException(),
+		};
+
+		public static List<List<CellState>> FromInput(this List<List<char>> board) {
+			return board.Select((row) => row.Select((c) => FromInput(c)).ToList()).ToList();
+		}
+
+        public static List<List<char>> ToInput(this List<List<CellState>> board) {
+			return board.Select((row) => row.Select((state) => ToInput(state)).ToList()).ToList();
+		}
+    }
+
+    public class WorkingBoard {
+		readonly List<List<CellState>> _board;
+
+        public WorkingBoard(List<List<CellState>> board) {
+			this._board = board;
+		}
+
+        public WorkingBoard(List<List<char>> board) {
+			this._board = board.FromInput();
+		}
+
+        public string Display() {
+			return string.Join(
+                Environment.NewLine, 
+                _board.ToInput().Select((row) => string.Join("", row))
+            );
+		}
+
+        public ReadOnlyCollection<ReadOnlyCollection<CellState>> Board {
+			get => _board.Select((row) => row.AsReadOnly()).ToList().AsReadOnly();
+		}
+
+		public event Action<WorkingBoard>? AlgorithmStep;
+
+		public void RunIdaStar() {
+			throw new NotImplementedException();
+		}
+    }
+
+}
+
 /*
     IDA*( state s, int g, threshold t ) {
         h = Eval( s );