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).
from sys import stdin
from sys import stdout
from math import ceil
#Fast IO
def glis():
	return list(map(int,(stdin.readline().strip().split())))

def gtis():
	return tuple(map(int,stdin.readline().strip().split()))

def gstr():
	return stdin.readline().strip().split()

def gi():
	return int(stdin.readline().strip())

def gcl():
	s=stdin.readline().strip().split()
	return list(s[:len(s)-1])

def p(x,end='\n'):
	stdout.write(str(x)+end)

def pi(s):
	p(' '.join(map(str,s)))

def main():
	t=gi()
	p(ceil((t**2)/2))
	y=t
	i='C'
	while y>0:
		for k in range(t):
			if k==t-1:
				p(i)
				if t%2!=0:
					if i=='C':
						i='.'
					else:
						i='C'
			else:
				p(i,end='')
				if i=='C':
					i='.'
				else:
					i='C'
		y-=1


if __name__=='__main__':
	main()