You are under aerial attack, so you need to dig a tunnel fast to help everyone

escape, from $A$ to $B.$

Load up the file underground.csv on Moodle. The exact same code as last week

can be used for loading it$.$

This data shows the underground conditions of the terrain, as obtained using

ground penetrating radar. The $"*"$ denotes solid rock that you cannot dig

through. A and B show where you start, and where you must get to$.$ The

numbers denote the number of minutes that it would take you to dig through

this part of the ground.

You can dig North, South, East or West, but not diagonally.

You have $2$ hours to find the quickest possible route from $A$ to $B.$ Then the

digging must start.