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).
n = int(input())
if n % 2 == 0:
        print(n*n // 2)
else:
        print((n*n+1) // 2)
for i in range(1, n+1):
        for j in range(1, n+1):
                if (i % 2 == 1 and j % 2 == 1) or (i % 2 == 0 and j % 2 == 0):
                        print('C', end='')
                else:
                        print('.', end='')
        print()
