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())
coders = 0
res = []
for i in range(n):
	res.append([])
	if i % 2 == 0:
		for j in range(n):
			if j % 2 == 0:
				res[i].append('C')
				coders += 1
			else:
				res[i].append('.')
	else:
		for j in range(n):
			if j % 2 == 1:
				res[i].append('C')
				coders += 1
			else:
				res[i].append('.')
print(coders)
for i in range(n):
	print(res[i])