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 == 1: print("1"); print("C")
if n%2 == 0: #if its even 
    output = int(n*(n/2))
    print(output)
    is_c = True
    c_first = True
    string = ""
    for i in range(n):
        if c_first: is_c = not is_c

        for j in range(n):
            if is_c:
                string += "C"
            else:
                string += "."
            is_c = not is_c
            c_first = not c_first

        
        print(string)
        string = ''
        
    
else:
    is_c = True
    string = ""
    x = (round(n/2) + 1)
    y = round(n/2)
    output= int(x**2 + y**2)
    print(output)
    for i in range(n):
        for j in range(n):
            if is_c:
                string += "C"
                output += 1
            else: string += "."
            is_c = not is_c
        print(string)
        string = ''
