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).
from sys import stdin

def main():
    n = int(stdin.readline().strip())
    print(n * n // 2 + (n & 1))
    s0 = ('C.' * (n // 2 + 1))[:n]
    s1 = ('.C' * (n // 2 + 1))[:n]
    for i in range(n):
        print((s0, s1)[i & 1])


main()
