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).
a = int(input())
if  a % 2 == 1:
    print(a ** 2 // 2 + 1)
else:
    print(a ** 2 // 2)
for i in range(a):
    b = ''
    if i % 2 == 0:
        for g in range(a):
            if g % 2 == 0:
                b += 'C'
            else:
                b += '.'
    else:
        for g in range(a):
            if g % 2 == 0:
                b += '.'
            else:
                b += 'C'
    print(b)