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.
The first line contains an integer *n* (1 ≤ *n* ≤ 1000).
if __name__ == "__main__":
    side_squares = int(input())
    squares = side_squares * side_squares
    if squares % 2 == 0:
        coders = squares // 2
    else:
        coders = squares // 2 + 1
    print(coders)
    for line in range(side_squares):
        line_config = ""
        for square in range(side_squares):
            if line % 2 == 0:
                if square % 2 == 0:
                    line_config += "c"
                else:
                    line_config += "."
            else:
                if square % 2 == 0:
                    line_config += "."
                else:
                    line_config += "c"
        print(line_config)