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());l=[];st1="C.";st2=".C"
if n%2==0:
	for i in range(n//2):
		l.append(st1*(n//2))
		l.append(st2*(n//2))
else:
	for k in range((n-1)//2):
		l.append(st1*((n-1)//2)+"C")
		l.append(st2*((n-1)//2)+".")
	l.append(st1*((n-1)//2)+"C")
if n % 2 == 0:
	print((n / 2) * n)
else:
	print(int((n / 2) * n)+1)
for j in l:
	print(j)