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())
s = []
sum = 0
for i in range(n):
	s1 = ''
	if i%2 != 0:
		for j in range(n):
			if j%2 != 0:
				s1 += 'C'
				sum += 1
			else:
				s1 += '.'
		s.append(s1)
	else:
		for j in range(n):
			if j%2 == 0:
				s1 += 'C'
				sum += 1
			else:
				s1 += '.'
		s.append(s1)
		
print(sum)
for i in range(n):
	print(s[i])