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())
rows = [(["C", "."] * (n // 2) + ["C"] * (n % 2)), ([".", "C"] * (n // 2) + ["."] * (n % 2))]
print((n ** 2) // 2 + n % 2) 
for i in range(0, n):
    print("".join(rows[i % 2]))