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==0):
	print(int(n*n//2))
	k = n
	while(k>0):
		print('C.'*int(n//2))
		print('.C'*int(n//2))
		k-=2
else:
	if(n==1):
		print(1)
		k = n
	else:
		a,b = n//2+1,n//2
		print(a**2+b**2)
		k = n
		while(k>0):
			print('C.'*(a-1)+'C')
			if(k>1):
				print('.C'*(a-1)+'.')
			k-=2