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 main():
    n = int(input())

    ans = 0

    crow1 = n // 2
    row1 = 'C.' * (n // 2)
    if n % 2 == 1:
        row1 = row1 + 'C'
        crow1 += 1

    crow2 = n // 2
    row2 = '.C' * (n // 2)
    if n % 2 == 1:
        row1 = row1 + '.'

    i = 0
    out = []
    while i < n:
        out.append(row1)
        ans += crow1
        i += 1
        if i < n:
            out.append(row2)
            ans += crow2
            i += 1

    print(ans)
    print('\n'.join(out))

    



if __name__ == "__main__":
    main()