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())
z=0
a=[]
if n%2==0:
	for i in range(n):
		if i%2==0:
			z+=n//2
			t="c."*(n//2)
			a.append(t)
		else:
			t=".c"*(n//2)
			a.append(t)
			z+=n//2
else:
	for i in range(n):
		if i%2==0:
			z+=n//2+1
			t="c."*(n//2)+"c"
			a.append(t)
		else:	
			z+=n//2
			t=".c"*(n//2)+"."
			a.append(t)
print(z)
for i in range(len(a)):
	print(a[i])			