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())
if n%2==0:
    print(int(n**2/2))
if n%2!=0:
    print(math.ceil(n**2/2))
for i in range(1,n+1):
    if i%2!=0:
        if n%2!=0:
            print("C." *int(n/2)+'C')
        elif n%2==0:
            print("C." * int(n/2))
    elif i%2==0:
        if n%2!=0:
            print(".C" * int(n/2)+'.')
        elif n%2==0:
            print(".C"*int(n/2))
