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())
def fc(n):
    p=0
    for x in range(1,n+1):
        print('C',end='')
        p+=1
        if p==n:
            break
        print('.',end='')
        p+=1
        if p==n:
            break
    #print('\n')    

def fdot(n):
    p=0
    for x in range(1,n+1):
        print('.',end='')
        p+=1
        if p==n:
            break
        print('C',end='')
        p+=1
        if p==n:
            break
   # print('\n')    
if n%2==0:
    print((n*n)//2)
    p=0
    for x in range(1,n+1):
        fdot(n)
        p+=1
        print('')
        if p==n:
            break
        fc(n)
        p+=1
        print('')
        if p==n:
            break
else:
    temp=(n*n)//2
    print(temp+1)
    p=0
    for x in range(1,n+1):
        fc(n)
        p+=1
        print('')
        if p==n:
            break
        fdot(n)
        p+=1
        print('')
        if p==n:
            break

