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).
def get_board(n: int) -> list[list]:
    board = []
    for i in range(n):
        row = []
        for j in range(n):
            if (i % 2 == 0 and j % 2 == 0) or (i % 2 == 1 and j % 2 == 1): row.append("C")
            else: row.append('.')
        board.append(row)
    return board

n = int(input())
board = get_board(n)
answer = n ** 2 // 2
answer = answer if n % 2 == 0 else answer + 1
print(answer)
for row in board:
    print("".join(row))
    

