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).
import math
n = int(input())

answer = math.ceil((n*n)/2.0)

list1 = [['.' for i in range(n)] for j in range(n)]

for i in range(n):
	for j in range(n):
		if (i%2 == 0 and j%2 == 0):
			list1[i][j] = 'c'
		elif (i%2 == 1 and j%2 == 1):
			list1[i][j] = 'c'
print(answer)
for i in range(n):
	for j in range(n):
		print(list1[i][j],end='')
	print()