DS&A for Beginners Minor Code Correction

code.cs

@@ -0,0 +1,42 @@
+using System;
+using System.Collections;
+
+
+public class Stack {
+
+	// Old Code:
+	// ArrayList stack = new();
+
+	// Corrected Code:
+    ArrayList stack = new ArrayList();
+
+    public Stack() {}
+
+    public void Push(int n)
+    {
+        stack.Add(n);
+    }
+
+    public int Pop()
+    {
+        if (Size() > 0)
+        {
+            int ele = (int)stack[stack.Count-1];
+            stack.RemoveAt(stack.Count-1);
+            return ele; 
+        }
+        return -1;
+    }
+
+    public int Size()
+    {
+        return stack.Count;
+    }
+}
+
+
+// Add this to allow compilation and execution
+class Program {
+	public static void Main(string[] args) {
+	}
+}