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