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())

print(n * n // 2 if n % 2 == 0 else n * (n // 2) + n // 2 + 1)

a = [['.' for i in range(n)] for j in range(n)]
b = [''] * n

for i in range(n):
    for j in range(n):
        pos_1 = i % 2 == 0 and j % 2 == 0
        pos_2 = i % 2 == 1 and j % 2 == 1
        if pos_1 or pos_2:
            a[i][j] = 'C'
    b[i] = ''.join(a[i])

for i in range(n):
    print(b[i], flush=False)
