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())

if n % 2 == 0:
  print(str(n/2*n))
else:
  print(str((n//2)*(n//2) + (n//2+1)*(n//2+1)))

evenrow = ''
oddrow = ''
for i in range(n):
  if i % 2 == 0:
    evenrow += 'C'
    oddrow += '.'
  else:
    evenrow += '.'
    oddrow += 'C'

for i in range(n):
  if i % 2 == 0:
    print(evenrow)
  else:
    print(oddrow)

      



