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())
if x%2 == 0:
	print(int(x*x/2))
elif x%2 == 1:
	print(int((x+1)*(x+1)/4 + (x-1)*(x-1)/4))
if x%2 == 1:	
	for i in range(x):
		if i%2 == 0:
			print(int((x-1)/2)*"C.",end="")
			print("C")
		elif i%2 == 1:
			print(int((x-1)/2)*".C",end="")
			print(".")
if x%2 == 0:
	for i in range(x):
		if i%2 == 0:
			print("C.")
		elif i%2 == 1:
			print(".C")