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())
mat = ""

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