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())
if n % 2 == 0:
    print((n * n) // 2)
else:
    print((n // 2 * n) + (n - n // 2))
s1 = "."
s2 = "C"
for i in range(n - 1):
    if i % 2 == 0:
        s1 = s1 + "C"
        s2 = s2 + "."

    else:
        s1 = s1 + "."
        s2 = s2 + "C"
for i in range(n):
    if i % 2 == 0:
        print(s2)
    else:
        print(s1)