I am working on a simple routine in Python which conditionally applies a discount to a monetary amount so long as it is above a certain threshold:

```
money = input("how much are you paying ")

discount = 0.2
num = 20

float(money)

payment = money*discount

if money > num:
    print("you are paying " + money)
else:
    print("you are paying " + payment )

```

However, the above code is not working as expected with an error thrown from the line:

`payment = money*discount`

Could anyone please advise as to what I'm doing wrong?