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).
chessboard = input()
chessboard = int(chessboard)

#odd =  n^2 - 1 / 2
#even = n^2 / 2

if chessboard % 2 == 0:
    print(int((chessboard ** 2) / 2))
else:
    print(int(((chessboard ** 2) - 1) / 2))

temp = 0

for i in range(0,chessboard):
    for j in range(0,chessboard):
        if temp == 0:
            print('C',end='')
            temp = temp + 1
        else:
            print('.',end='')
            temp = 0
#special case for even
    if chessboard % 2 == 0:
        temp = 1 - temp
    print('')
