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
z = int(input())
n = 0
k = 0
s = ''
for x in range(z):
 for y in range(z):
  n=n+1
  if math.fmod(n,2)!=0: 
   k=k+1
   s=s+'C'
  else: s=s+'.'
print(k)
print(s)