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).
def int_lst_input():
    return [int(val) for val in input().split()]


def int_input():
    return int(input())


def print_lst(lst):
    print(' '.join([str(val) for val in lst]))


def solve():
    n = int_input()

    grid = []
    c = 0

    even = ['C' if i % 2 == 0 else '.' for i in range(n)]
    odd = ['C' if i % 2 == 1 else '.' for i in range(n)]

    for i in range(n):
        if i % 2 == 0:
            grid.append(even)
        else:
            grid.append(odd)

    print(c)
    for row in grid:
        for c in row:
            print(c, end='')
        print()


if __name__ == '__main__':
    solve()
