[Closed] replacing a shed roof - corrugated sheets or felt?

The cheapy shed in the garden leaks and i cant afford to replace it with a proper substantial thing at the moment so was planning on re-roofing it.

Its got boards covered with felt nailed on at the moment but the felt is paper thin.

So whats easiest way to fix it, just re-felt it with some more substantial felt, or can i put those corrugated bitumen sheets directly over the boards (with the proper ridge bits)?

Whats the easiest way?