I don't understand, why output have (2,3),(3,3),(4,3) graves? When Lara will dig out the second grave with treasure, she at once will go back, it is true?

I guess the statement "As soon as Lara finds the second treasure (and goes immediately to buy the usual bottle of champagne), a new alarm system (of "LaraKiller" brand) will be set off." should not be there in the question.
I wrote my program with the assumption that the alarm can ring even before Lara has found the treasure and i got AC 0.031.
I used recursion to do the whole thing(The problem reverts to a (N-2)X(M-2) cemetry problem after each round).