how to delete characters that are not a letter?

Question

I must remove the characters that are not a letter and only leave the ones that are letters and also the spaces.
anexo el código que he hecho hasta ahora usando los codigos a ascii

https://code.sololearn.com/c2GFr1a591TQ/?ref=app

Answer 1

Give a sample string so I can check that my code does what you need as I might need to change the function I've used (from the cctype header).