I don't understand why the Answer is that
in the input of the problem
specialy the one [1,1]=2

{*2*} 2 -1 2 -1
3 2 2 7 2
1 7 7 5 7
1 5 5 -1 5
-1 1 4 -1 4

if you know the answer please help me.
with best wishes
pooya

I forgot this problem but all i remember is that
it uses XOR between numbers (Integer!)
and it was so cute...

mmm
I think it also needs BFS to find nearst branch?
is it right?

Yours
Aidin