On a chessboard, positions are marked with letters between a and h for the column and a
number between 1 and 8 for the row. The first place on the board, a1, is black. The next
is white, alternating across a row. Odd rows start with black, even rows start with white.
Give a 2 character input string with a letter (a-h) and a number (1-8), print "Black" or
"White" indicating if the square is black or white.