feat: Add factorial calculation program using math.factorial

Author: yrobla

test.py

@@ -0,0 +1,15 @@
+import math
+
+def calculate_factorial(n: int) -> int:
+    """Calculate the factorial of a given number using math.factorial."""
+    if n < 0:
+        raise ValueError("Factorial is not defined for negative numbers.")
+    return math.factorial(n)
+
+if __name__ == "__main__":
+    number = int(input("Enter a number to calculate its factorial: "))
+    try:
+        result = calculate_factorial(number)
+        print(f"The factorial of {number} is {result}.")
+    except ValueError as e:
+        print(e)