Why is it wrong?

Question

def spell(txt,n):
if n==0:
return
else:
print(txt[n-1])
print(spell(txt,n-1))
txt = input()
n = len(txt)
spell(txt,n)

Answer 1

Thank you very much. It's up and running

Answer 2

How to do that

Answer 3

It from intermediate Python 19