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).
x = int(input())
if x % 2 == 0:
    print(int((x / 2) * x))
    for i in range(int(x/2)):
            print('c.'*(x-int(x/2)))
            print('.c'*(x-int(x/2)))

if x % 2 != 0:
    print((int((x+1)/2) *x)-int(x/2))
    for i in range(x):
        if i % 2 == 0:
            a = 'c.' * (x-int(x/2))
            a = list(a)
            del a[-1]
            print(''.join(a))
        else:
            b = '.c' * (x-int(x/2))
            b = list(b)
            del b[-1]
            print(''.join(b))