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())
print(math.ceil((n*n)/2))

x = ''
for z in range(0 , n , 1):
    if z%2 == 0:
        x += 'C'
    else:
        x += '.'

y = ''
for z in range(0 , n , 1):
    if z%2 == 0:
        y += '.'
    else:
        y += 'C'

for q in range(0 , n , 1):
    if q%2 == 0:
        print(x)
    else:
        print(y)
