n = 8, k = 3
one computer already has got prog installed, so you start copying from that one.
you copied to any one (to exactly one as problem requires), 1 hour passed, k = 2 (2 cables left).
you copied to next(any) one, 2 hours passed, k = 1 (and 1 cable left), copied to next - 3 hours passed and no cables left !! at the moment there are 4 computers remaining without programm, so as i see its impossible to copy to all computers, becuase no cables left ...
how the hell output is 4 ?? and how you use them 3 cables to copy to all computers ...
Whats wroung in this ???
help me please, thanks !

cables can be reused