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())
if n%2 == 1:
    a = n//2 + 1
    b = n - a
    print(a**2 + b*(a - 1))
else:
    a = n//2
    print(a * n)
for i in range(1, n+1):
    if i%2 == 0:
        point = False
    else:
        point = True
    for j in range(1, n + 1):
        if point :
            print('C', end='')
            point = False
        else:
            print(".", end='')
            point = True
    print()