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())
t=1
l=[]
k=0
for i in range(n) :
    S=''
    if t==1 :
        for j in range(n) :
            if (j+1)%2!=0 :
                S=S+'C'
                k=k+1
            else :
                S=S+'.'
    if t==2 :
        for j in range(n) :
            if (j+1)%2==0 :
                S=S+'C'
                k=k+1
            else :
                S=S+'.'
    if t==1 :
        t=2
    else :
        t=1
    l.append(S)
print(k)
for i in range(n) :
    print(l[i])
                
        
    
    
