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).
f=lambda:map(int,input().split())
n=int(input())
print([n**2//2,(n**2+1)//2][n%2])
for i in range(1,n+1):
    if i%2==0:
        [print('C.'[j % 2],end='') for j in range(1, n + 1)]
    else:
        [print('.C'[j % 2],end='') for j in range(1, n + 1)]
    print()
