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).
# cf 384 A 800
n = int(input())

rows = []
c = 0

for i in range(n):
    c += (n // 2)
    if n % 2 != 0 and i % 2 == 0:
        c += 1
    if i % 2 == 0: # even
        row = [ "C." ] * (n // 2)
        if n % 2 == 1:
            row += [ "C" ]
    else:
        row = [ ".C" ] * (n // 2)
        if n % 2 == 1:
            row += [ "." ]
    rows.append(row)

print(c)
for row in rows:
    print("".join(row))
