def factorial(n: int) -> int:
    if n < 2:
        return n
    else:
        return n * factorial(n-1)

def factorial_iter(n: int) -> int:
    fact = 1
    # Grab absolute value to ensure n is a positive integer
    n = abs(n)
    for i in range(2, n+1):
        fact *= i
    return fact

user_input = int(input("Insert number to calculate factorial for: "))

# Avoid recursion limit
if user_input < 1000:
    print(f"Recursive factorial {user_input}: {factorial(user_input)}")
print(f"Iterative factorial {user_input}: {factorial_iter(user_input)}")