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

a=int(input())
print(math.ceil(pow(a,2)/2))
if a%2==0:
    for i in range(a):
        if(i%2==0): print('C.'*int(a/2))
        else: print('.C'*int(a/2))
else:
    for i in range(a):
        if(i%2==0): print('C.'*int(a/2)+'C')
        else: print('.C'*int(a/2)+".")