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(int(n*n/2))
else :
    print(int((n*n+1)/2))
for i in range(0,n):
    for j in range(0,n):
        if i%2==0:
            if j%2==0:
                print ('c',end="")
            else :
                print ('.',end="")
                
        else :
            if j%2==0 :
                print ('.',end="")
            else :
                print ('c',end="")
    print ("")
                