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