Orange Boy loves walking. One day, he wanna walk from
the boy can walk in three types:
to by costing A yuan
to by costing B yuan
to or by costing C yuan
He must walk from
What's the minimal cost???!!?!
Path is this:
(1,1) -> (2,2) -> (3,3) -> (2,2) -> (3,3) -> (4,3)
note that he must visit them in order.