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).
# https://codeforces.com/contest/384/problem/A

def sol(n):
    if(n&1):
        ans = (pow(n,2) + 1)//2
    else:
        ans = (pow(n,2))//2
    if(n==1):
        print(ans)
        print('C')
    else:
        print(ans)
        s = ''
        a = ''
        for i in range(n):
            if(i%2==0):
                s+='C'
                a+='.'
            else:
                s+='.'
                a+='C'
        for i in range(n):
            if(i%2==0):
                print(s)
            else:
                print(a)
                    
                
        
n = int(input())
sol(n)