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


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