Cross

You have been given a board. It has $n$ rows and $m$ columns. Some spaces on this board are empty, and others are filled with squares. Squares are marked by a "$\ast$" and empty spaces by a "$\cdot$". Your goal, is to check if there is a cross in the board. A cross is formed by an intersecting row and column, both composed entirely of squares (the intersection **does not** have to be centered li