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