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