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())
output = 0
text = []
if n%2 == 0:
    is_c = False
    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"
                output +=1
            else:
                string += "."
            is_c = not is_c
            c_first = not c_first

        
        text.append(string)
        string = ''
        
    
else:
    is_c = True
    string = ""
    for i in range(n):
        for j in range(n):
            if is_c:
                string += "C"
                output += 1
            else: string += "."
            is_c = not is_c
        text.append(string)
        string = ''
print(output)
print("\n".join(text))
