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 = ''
c = 0

for x in range(n):
	for y in range(n):
		if (x % 2 == 0 and  y % 2 == 0) or (x % 2 == 1 and  y % 2 == 1):
			s += 'C'
			c += 1
		else:
			s += '.'
			
	s += '\n'

print(c)
print(s)
 	   								   	  								 		