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).
if __name__ == '__main__':
    n = int(input())
    s = n * n

    print((s // 2) + (s % 2))
    line_1, line_2 = 'C.' * ((n // 2) + 1), '.C' * ((n // 2) + 1)
    for i in range(n):
        if i % 2 == 0:
            print(line_1[:n])

        else:
            print(line_2[:n])
