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 == 0:
    print((n*n)//2)
else:
    print((n//2 + n%2)*(n//2 + n%2) + (n//2)*(n//2))
for j in range(n):
    for i in range(n):
        if i%2 == j%2:
            print('C', end='')
        else:
            print('.', end='')
    print()
