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).
x=int(input())
p=['C' for i in range((x+1)//2)]
q=p.copy()
q.pop()
if x%2==0:
	print((x//2)*x)
	for i in range(x//2):
		print(".".join(p)+".")
		print("."+".".join(p))
else:
	print(((x+1)//2)*x-(x//2))
	for i in range(x//2):
		print('.'.join(p))
		print('.'+'.'.join(q)+'.')
	print('.'.join(p))