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())
result = n*(n//2)
if n % 2 == 1:
    result += n // 2 + 1
print(result)
for j in range(n):
    result = ''
    if j % 2 == 0:
        for i in range(n):
            if i % 2 == 0:
                result += 'c'
            else:
                result += '.'
    else:
        for i in range(n):
            if i % 2 == 0:
                result += '.'
            else:
                result += 'c'
    print(result)