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=""
for i in range(n+1):
	if(i%2==0):
		s+='C'
	else:
		s+='.'
ss=[]
ans=0
for i in range(n):
	if(i%2==0):
		ss.append(s[0:n])
		ans+=s[0:n].count('C')
	else:
		ss.append(s[1:n+1])
		ans+=s[1:n+1].count('C')
print(ans)
for i in ss:
	print(i)