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).
# Codeforces A. Coder
# Created by Abdulrahman Elsayed on 13/01/2021

n = int(input())

if ((n % 2 == 0)):
    print(int((n * n) / 2))
else:
    print(int((n * n) / 2 + (1 / 2)))

for i in range(n):
    if ((i % 2) == 0):
        for j in range(n):
            if ((j % 2) == 0):
                print('C', end='')
            else:
                print('.', end='')
    else:    
        for j in range(n):
            if ((j % 2) == 0):
                print('.', end='')
            else:
                print('C', end='')
    print('')
            
    