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 == 1:
	print(1)
	print("C")
else:
	c_count = 0
	ans = []

	for i in range(1,n+1):
		a = []
		for j in range(1,n+1):
			if (i%2 != 0) :
				if j%2 != 0:
					a.append("C")
					c_count += 1
				else:
					a.append(".")
			else:
				if j%2 == 0:
					a.append("C")
					c_count += 1
				else:
					a.append(".") 	
		ans.append(a)


	print(c_count)
	for i in ans:
		for j in i:
			print(j, end="")
		print()
