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())

m = ''
for i in range(n):
     for j in range(n):
          if i%2 == 0 and j%2 ==0 :
               m +='C'
          elif i%2 != 0 and j%2 !=0 :
               m +='C'
          else:
               m +='.'
     m +='\n'
print(int((n*n)/2+ (n*n)%2))
print(m)
