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())

    r = ((n + 1)//2)**2 + (n//2)**2

    print(r)

    s1 = []
    s2 = []
    for i in range(1, n + 1):
        if i % 2 == 1:
            s1.append('C')
            s2.append('.')
        else:
            s1.append('.')
            s2.append('C')

    s1 = "".join(s1)
    s2 = "".join(s2)

    for i in range(1, n + 1):
        print(i % 2 == 1 and s1 or s2)

main()