I agree with you.
When I am checking best path then I have got sometimes a little better solution than expected.

100% correct!! This comment is sooo close to being a spoiler, but I can't complain, as it probably saved me hours.

I changed the default setup's variable k to private. The reference solution also uses private variable k.

this is encouraged, don't worry

These are intended because I want to sound cute > <

@Nlaa could you fix it?

This looks to generate all kinds of cases such son older than the father, ages are negative .

time to learn about dp... I NEED to solve this

Thank you for this hint! I was stuck with this problem for so long but finally managed to solve it thanks to dynamic programming...

The latter.

I modified test driver, should be fine now.

You're not always asked to move to the lower right corner. The goal-coordinated can be any point in the grid.

Which language were you using?

Well, this is exactly why the cata's description says "we assume that 0 ^ 0 = 1".