having trouble with challenge: coupon codes

I am having trouble with challenge: coupon codes. do you know what I am doing wrong? this is  what I'm supposed to do and what I did: 

what I'm supposed to do:

Travis can’t find the cleats at a local store, so he wants to include the shipping cost in the final price. Shipping costs can vary, so he decides to let the user enter the shipping cost themselves.

• Add a new input() prompt that asks the user to enter a shipping cost.
• Add the entered shipping cost to the final price.

You’ll need to store the result of the input() call in a new variable. Remember that the shipping cost may include cents, like 7.99.

what I did

base_price = input("Enter cart total: ")

# Available coupon codes include 15% off and $12 off.
percent_discount = float(base_price) - float(base_price) * .15
fixed_discount =  float(base_price) - 12

# Pick the coupon that offers the best discount.
final_price = min(fixed_discount, percent_discount)
print("Your best price is $" + str(round(final_price, 2 )) )
shipping_cost = input("Enter shipping cost: ")
final_price = shipping_cost + 
print(final_price)

please answer soon!

Hi, 

This is the challenge you are referring to: https://www.khanacademy.org/computing/intro-to-python-fundamentals/x5279a44ae0ab15d6:computational-thinking-with-variables/x5279a44ae0ab15d6:arithmetic-expressions/pc/coupon-codes

What you did is giving this error: Traceback (most recent call last): File "main.py", line 11 final_price = shipping_cost + ^ SyntaxError: invalid syntax

I think your main problem is with input().

Maybe you can use something like this to convert shipping_cost to a float so you can add it to the final_price:

shipping_cost = input("Enter shipping cost: ")

 final_price = final_price + float(shipping_cost)

print(final_price)