The official statement of a problem is always the one in the PDF document. The HTML version of the statement is also given to help you, but may contain some content that is not well displayed. In case of doubt, always use the PDF.
Input
5 6 .X.... .....X ...XXX .....X ...X.X 4 4 X... ..XX ...X .X.X 0 0
Output
bufff ui ui ui
