0 said when you are surprised, pleased, disappointed, etc. -- vaya
1 used to introduce an idea that you have just thought of, or something that you have just remembered -- ¡ah!
2 written abbreviation for the US state of Ohio: used in addresses -- abreviatura escrita de “Ohio”
3 indicates surprise, disappointment, sympathy, etc. -- oh
4 used at the beginning of a sentence, especially a reply -- oh
We can complete it step by step however long the road is and it can't be completed however short the road is if you don't even mark your footprint.
Podemos completarlo paso a paso, por muy largo que sea el camino, y no se puede completar, por corto que sea el camino, si ni siquiera marcas tu huella.