[Grammar] What money they had managed to save

[Osya Bender]

They had no food, no blankets, no weapons save for the standard long knives all Valemen wore, no camping gear or foul-weather equipment, and worst of all, no money. The ale house keeper hadn't paid them in a month. What money they had managed to save from the month before had been lost in the fire along with everything else they owned. They had only the clothes on their backs and a growing fear that perhaps they should have stuck with the nameless stranger a bit longer.
The Scions of Shannara by Terry Brooks

I can't understand what meaning "what" has in the sentence. It seems to me that this "what" could be omitted and the sentence would look fine. I'm puzzled:shock:
Thank you.

 

[Osya Bender]

Oh, I think I have found something similar in a Russian dictionary:

give me what books you have
what little he did say was always well said
he will give what help he can

 

[MikeNewYork]

In this use, "what" is an adjective modifying "money". Synonyms would be "whatever" or "any". It refers to a sum of money that they had lost.