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).
a=int(input())
if a%2==0:
	print((a**2)//2)
elif a%2!=0:
	print(((a**2)+1)//2)
p=""
for i in range(a):
	if i%2==0:
		p+="C"
	elif i%2!=0:
		p+="."
q=""
for i in range(a):
	if i%2!=0:
		q+="C"
	elif i%2==0:
		q+="."
for j in range(a):
	if j%2==0:
		print(p)
	elif j%2!=0:
		print(q)