The question says : "if it is possible to choose from the
two lists of integers such two numbers that their sum would
be equal to 10 000 ...", implying that any two numbers will
do, regardless of whether they are from the same list or
not. However, it means, choose from the two lists of
integers such two numbers, one from each list...

 It means that first number from first list and second number from
second list

>  It means that first number from first list and second number from
> second list

I haven't send the solution yet, because I suspected this trouble. My
solution is for ANY combination of numbers. Does it mean that I will
get WA ? Was it checked ?

YES! When I checked ANY combinations i got WA. I stopped checking it
and got AC.