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).
n = int(input())
if n%2 == 0:
	res = (n*(n//2))
else:
	res = (n*(n//2) + (n//2) + 1)
print (res)
turn = 0
for i in range(n):
	if n%2 == 0:
		turn = 1-turn
	for j in range(n):
		if turn == 1:
			print ("C", end="")
			turn = 0
		else:
			print (".", end="")
			turn = 1
	print ()
