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())
c = n * n
s = list(list("C" for i in range(n)) for j in range(n))
for i in range(n):
    if i % 2 == 0:
        for j in range(1, n, 2):
            s[i][j] = "."
            c -= 1
    if i % 2 != 0:
        for j in range(0, n, 2):
            s[i][j] = "."
            c -= 1
print(c)
for i in range(n):
    print(*s[i], sep="")
