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).
a = int(input())
if (a * a) % 2 == 0:
    print(a * a // 2)
    for i in range(a):
        if i % 2 == 0:
            for i in range(a // 2):
                print("C.",end="")
        else:
            for i in range(a // 2):
                print(".C",end="")
        print()
else:
    print(a * a // 2 + 1)
    for i in range(a):
        if i % 2 == 0:
            for i in range(a // 2):
                print("C.",end="")
            print("C",end="")
        else:
            for i in range(a // 2):
                print(".C",end="")
            print(".",end="")
        print()