Perfect number of nights in Prague?

Hello. I am traveling in late August to Central Europe for 8 nights with my family (3 adults in our 20s plus my parents, no children). Should we do:

6 nights Prague, 2 nights Cesky Krumlov

4 nights Prague, 2 nights Cesky Krumlov, 2 nights Budapest

4 nights Prague, 1 night Cesky Krumlov, 3 nights Budapest

3 nights in Prague, 2 nights Cesky Krumlov, 3 nights Budapest

Thanks,