diff --git a/main.py b/main.py
index 9c5fb5d..deaf7e9 100644
--- a/main.py
+++ b/main.py
@@ -1,23 +1,9 @@
-def nth_fibonacci(n):
-  
-    # Base case: if n is 0 or 1, return n
-    if n <= 1:
-        return n
-      
-    # Recursive case: sum of the two preceding Fibonacci numbers
-    return nth_fibonacci(n - 1) + nth_fibonacci(n - 2)
-
-n = 5
-result = nth_fibonacci(n)
-print(result)
-
-
 # Function to calculate the nth Fibonacci number using memoization
 def nth_fibonacci_util(n, memo):
 
     # Base case: if n is 0 or 1, return n
     if n <= 1:
-        return n
+        return m
 
     # Check if the result is already in the memo table
     if memo[n] != -1:
@@ -30,21 +16,25 @@ def nth_fibonacci_util(n, memo):
     return memo[n]
 
 
-# Wrapper function that handles both initialization
-# and Fibonacci calculation
 def nth_fibonacci(n):
-
-    # Create a memoization table and initialize with -1
-    memo = [-1] * (n + 1)
-
-    # Call the utility function
-    return nth_fibonacci_util(n, memo)
-
-
-if __name__ == "__main__":
-    n = 5
-    result = nth_fibonacci(n)
-    print(result)
+    """
+    Calculate the nth Fibonacci number.
+    
+    Args:
+        n: A non-negative integer
+    
+    Returns:
+        The nth number in the Fibonacci sequence
+    
+    Raises:
+        TypeError: If n is not an integer
+        ValueError: If n is negative
+    """
+    if not isinstance(n, int):
+        raise TypeError("Input must be an integer")
+    if n < 0:
+        raise ValueError("Input must be non-negative")
+    return nth_fibonacci_util(n)
 
 
 
@@ -68,6 +58,5 @@ def nth_fibonacci(n):
     # Return the nth Fibonacci number
     return dp[n]
 
-n = 5
-result = nth_fibonacci(n)
-print(result)
+# Remove lines 57-59 entirely
+
diff --git a/test.py b/test.py
new file mode 100644
index 0000000..10977f2
--- /dev/null
+++ b/test.py
@@ -0,0 +1,21 @@
+import unittest
+from main import nth_fibonacci
+
+class TestFibonacci(unittest.TestCase):
+    def test_base_cases(self):
+        self.assertEqual(nth_fibonacci(0), 0)
+        self.assertEqual(nth_fibonacci(1), 1)
+
+    def test_positive_values(self):
+        self.assertEqual(nth_fibonacci(2), 1)
+        self.assertEqual(nth_fibonacci(5), 5)
+        self.assertEqual(nth_fibonacci(10), 55)
+
+    def test_input_validation(self):
+        with self.assertRaises(TypeError):
+            nth_fibonacci('5')
+        with self.assertRaises(ValueError):
+            nth_fibonacci(-1)
+
+if __name__ == '__main__':
+    unittest.main()