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())
board = []
count = 0
for i in range (0, n):
    row = []
    if i % 2 == 0:
        for j in range (0, n):
            if j % 2 == 0:
                row.append('C')
                count += 1
            else:
                row.append('.')
    else:
        for j in range (0, n):
            if j % 2 != 0:
                row.append('C')
                count += 1
            else:
                row.append('.')
    board.append(row)
print(count)
for row in board:
    print("".join(row))