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())

print((n ** 2 + 1) // 2)

k, mod_ = divmod(n, 2)
s1, s2 = 'C.' * k, '.C' * k

if mod_:
    s1, s2 = s1 + 'C', s2 + '.'

for i in range(n):
    print(s2 if i % 2 else s1)