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).
from math import ceil
n=int(input())
b=[]
print(ceil((n*n)/2))
for i in range(1,n+1):
    if i%2==1:
        print(*list('C'*ceil(n/2)),sep='.',end='')
        if n%2==0:
            print('.')
        else:
            print()
    else:
        print(*list('.'*ceil(n/2)),sep='C',end='')
        if n%2==0:
            print('C')
        else:
            print()