diff --git a/students_submissions/gcd_kjt6.py b/students_submissions/gcd_kjt6.py
new file mode 100644
index 0000000..0d4f0bc
--- /dev/null
+++ b/students_submissions/gcd_kjt6.py
@@ -0,0 +1,32 @@
+def gcd(a: int, b: int) -> int:
+    """
+    Calculate the greatest common divisor (GCD) of two integers a and b
+    using the Euclidean algorithm.
+    """
+    if not isinstance(a, int) or not isinstance(b, int):
+        print("Error: a and b must be integers.")
+        return None
+
+    if a == 0 and b == 0:
+        print("Error: GCD is undefined for both numbers being zero.")
+        return None
+    
+    a = abs(a)
+    b = abs(b)
+
+    # Base case
+    if b == 0:
+        return a
+
+    # Recursion
+    return gcd(b, a % b)
+
+# Test cases
+print(gcd(54, 24))  # Expected output: 6
+print(gcd(48, 18))  # Expected output: 6
+print(gcd(101, 10))  # Expected output: 1
+print(gcd(7, 13))   # Expected: 1 (both prime)
+print(gcd(-24, 36)) # Expected: 12 (negative number)
+print(gcd(0, 5))  # Expected: 5
+print(gcd(0, 0))  # Expected: Error + None
+print(gcd(10, "5"))  # Expected: Error + None
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