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).
from math import ceil
n = int(input())
if n%2 == 0:
    coders = (n**2)//2
    print(coders)
    ss = {0:'C.'*(n//2),1:'.C'*(n//2)}
    for i in range(0,n):
        print(ss[i%2])
else:
    coders = ceil(n/2)**2+ (n//2)**2
    ss = {0:'C.'*ceil(n/2),1:'.C'*ceil(n/2)}
    print(coders)
    for i in range(0,n):
        print(ss[i%2][0:n])