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).

import sys
def get_single_int ():
    return int (sys.stdin.readline ().strip ())
def get_string ():
    return sys.stdin.readline ().strip ()
def get_ints ():
    return map (int, sys.stdin.readline ().strip ().split ())
def get_list ():
    return list (map (int, sys.stdin.readline ().strip ().split ()))

#code starts here
n = get_single_int ()
if n % 2 == 0:
    print (n*(n//2))
else:
    print (n*(n//2) + 1)
for i in range (n):
    for j in range (n):
        if (i + j) % 2 == 0:
            print ('C', end = " ")
        else:
            print ('.', end = " ")
