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).
"""
██╗ ██████╗ ██╗    ██████╗  ██████╗  ██╗ █████╗
██║██╔═══██╗██║    ╚════██╗██╔═████╗███║██╔══██╗
██║██║   ██║██║     █████╔╝██║██╔██║╚██║╚██████║
██║██║   ██║██║    ██╔═══╝ ████╔╝██║ ██║ ╚═══██║
██║╚██████╔╝██║    ███████╗╚██████╔╝ ██║ █████╔╝
╚═╝ ╚═════╝ ╚═╝    ╚══════╝ ╚═════╝  ╚═╝ ╚════╝
"""                                        
__author__ = "Dilshod"
n = int(input())
if not n % 2:
	print(n * (n // 2))
else:
	print((n // 2 + 1) ** 2 + (n // 2) ** 2)
a = True
if n % 2:
	for i in range(n):
		ans = ""
		if a:
			ans += "C." * (n // 2) + "C"
			a = False
		else:
			ans += ".C" * (n // 2) + "."
			a = True
		print(ans)
else:
	for i in range(n):
		ans = ""
		if a:
			ans += "C." * (n // 2)
			a = False
		else:
			ans += ".C" * (n // 2)
			a = True
		print(ans)
