Answer 1

I think you can try using
dict dictionary {key : value}
or list [ ] or tupla ( )
For ex.
With index
even lenguage 1input
Odd lenguage 2 output

So you can add every in your list even+1 for ex in your recursive funtion

Maybe about 80% coherent funtional

#saying is easy but doing...
I think... very difficult challenge! ;)