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).
s = int(input())
add = 0
if s*s%2 != 0:
    add = 1
print((s*s)//2+add)
for x in range(s):
    for y in range(s):
        if x%2+y%2==2 or x%2+y%2 == 0:
            print("C", end = "")
        else:
            print(".", end = "")
    print()