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())
    s1 = ['.' if i % 2 == 1 else 'C' for i in range(n)]
    if s1[-1] == '.':
        s2 = s1[1:] + ['C']
    else:
        s2 = s1[1:] + ['.']
    s1, s2 = ''.join(s1), ''.join(s2)
    if n % 2 == 0:
        print(n // 2 + 1)
    else:
        print(n // 2)

    for i in range(n):
        if i % 2 == 0:
            print(s1)
        else:
            print(s2)


if __name__ == '__main__':
    main()