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 sys
input = sys.stdin.buffer.readline 

def process(n):
    if n % 2==0:
        a1 = (n*n)//2
    else:
        a1 = (n*n)//2+1
    sys.stdout.write(f'{a1}\n')
    for i in range(n):
        row = []
        for j in range(n):
            if (i+j) % 2==0:
                row.append('C')
            else:
                row.append('.')
        row = ''.join(row)
        sys.stdout.write(f'{row}\n')
        
n = int(input())
process(n)