Initial commit

WebApp/Helper.cs

@@ -0,0 +1,17 @@
+namespace WebApp;
+
+public static class Helper
+{
+    public static string ToLetters(int number)
+    {
+        var result = "";
+        while (number > 0)
+        {
+            number--; // Adjust for 1-based indexing
+            char letter = (char)('A' + (number % 26));
+            result = letter + result;
+            number /= 26;
+        }
+        return result;
+    }
+}