I don't know how do say in Czech but what I hear in London is:
"You must be joking!"
You can check in dictionaries...
Even more, I think, offering to use wxWidgets when U++ exists is a crime against humanity (I write for people who still haven't lost the ability to understand jokes...). Why? Wasting of human brain and computing power...
Of course. That is why am doing it for all these years.
Anyway, my experience is that showing this attitude "naked" plus ignoring other consequences simply does not work. Understood?