Time Limit: 1 second
Memory Limit: 256 megabytes
Iahub likes chess very much. He even invented a new chess piece named Coder. A Coder can move (and attack) one square horizontally or vertically. More precisely, if the Coder is located at position (x, y), he can move to (or attack) positions (x + 1, y), (x–1, y), (x, y + 1) and (x, y–1).
Iahub wants to know how many Coders can be placed on an n × n chessboard, so that no Coder attacks any other Coder.
On the first line print an integer, the maximum number of Coders that can be placed on the chessboard.
On each of the next n lines print n characters, describing the configuration of the Coders. For an empty cell print an '.', and for a Coder print a 'C'.
If there are multiple correct answers, you can print any.