Return the result rounded to two decimals.

Why are you using trunc?

Also, check the note, just in case you're using another value of Pi.

put these at the beginning of your code:

print("-->" + form_ + "<--")

print("-->" + txt + "<--")

this way you can see the inputs

Python

what language are you using?

I found it, but either examples and tests dont show a input that it occurs

errors are not random. you're trying to access data from a non-existant index of some container. the error message probably directs you to the line in your code where you made this mistake. try printing the inputs to see what you're dealing with

Passed random test but give me a random error. Dont give me any hint
just say "out of range" but no idea

n = 2m+1 holds for negative n just as for positive n. So,

they should have the same odd order

No.

I transforme negative to positive numbers, they should have the same odd order. for n<0 in my oppinion should be n=2m+1 or not?

31 or -31?

why 39 is odder than 31?
39 - 39,19,9,4
-31 - 31,15,7,3,1

Could be 8yu