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())
ans = N * N // 2 if N % 2 == 0 else N * N // 2 + 1
flg = True
print(ans)
for i in range(N):
    line = ""
    for j in range(N):
        if j % 2 == 0:
            if flg:
                line += "C"
            else:
                line += "."
        else:
            if flg:
                line += "."
            else:
                line += "C"
    flg = not flg
    print(line)
