diff --git a/students_submissions/gcd_ns336.py b/students_submissions/gcd_ns336.py
new file mode 100644
index 0000000..383673f
--- /dev/null
+++ b/students_submissions/gcd_ns336.py
@@ -0,0 +1,28 @@
+def gcd(a: int, b: int) -> int:
+    """
+    Calculate the greatest common divisor (GCD) of two integers a and b
+    using the Euclidean algorithm (recursive).
+    """
+
+    if not isinstance(a, int) or not isinstance(b, int):
+        raise TypeError("gcd expects two integers")
+
+    # Ensure non-negative values
+    a, b = abs(a), abs(b)
+
+    # Base case
+    if b == 0:
+        return a
+
+    # Recursive step
+    return gcd(b, a % b)
+
+
+# Test cases
+print(gcd(54, 24))    # Expected 6
+print(gcd(48, 18))    # Expected 6
+print(gcd(101, 10))   # Expected 1
+print(gcd(-36, 60))   # Expected 12
+print(gcd(0, 25))     # Expected 25
+print(gcd(0, 0))      # Expected 0 (convention, though mathematically undefined)
+