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).
n = int(input()) 
#n, m = map(int, input().split())
#s = input()
#c = list(map(int, input().split()))
print(n ** 2 // 2 + n % 2) # or (n ** 2 + 1) // 2
if n > 1:
    s = ''
    for i in range(n):
        if i % 2 == 0:
            s += 'C'
        else:
            s += '.'
    for i in range(n):
        if i % 2 == 0:
            print(s)
        else:
            print(s[::-1])
else:
    for j in range(n):
        if j % 2 == 0:
            print('C', end = '')
        else:
            print('.', end = '')    