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())
# 1 2 3 4  5  6 7 8
# 1 2 5 8 13 18
print(n * n // 2 + n % 2)
a = ['C' if i % 2 == 0 else '.' for i in range(n)]


def swap(a):
    for i in range(n):
        if a[i] == '.':
            a[i] = 'C'
        else:
            a[i] = '.'
    return a


for i in range(n):
    print(*a, sep='')
    a = swap(a)
