$]$ is the sample grind with answer $2$the city of hackerland can be represented as a $2$D grid size n x m$.$ Each cell is either an empty $($a dot character $.),$ an obstacle $($an asterisk$*),$ a start point $($ S$)$ or an end point $($E$).$ It can move up$,$ down, left and right. the goal is to move from the starting to the end point such that in the path, the min distance fro the obstacle is as large as possible. return the minimum distance. The distance between two points on the grid with coordinates $($r$1,$c$1)$ and $($r$2,$c$2)$ is calculated as absolute value of $|$r$1-$r$2|+|$c$1-$c$2|.$ write an algorithm in python