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).
# -*- coding: utf-8 -*-
n = int(input())

if n % 2 == 0:
    print(n*n // 2)
    print('\n'.join([('C.' if i % 2 == 0 else '.C') * (n//2) for i in range(n)]))
else:
    p = n // 2
    q = (n+1) // 2
    print(p*p + q*q)
    print('\n'.join([('C.' * p + 'C') if i % 2 == 0 else ('.C' * p + '.') for i in range(n)]))