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())
c_net=n
s1=str("c.")
s2=str(".c")
for temp in range(n-2,0,-2):
    #print(temp)
    c_net=c_net+2*temp

print(c_net)



if n%2==0:
    st1=s1*int(n/2)
    st2=s2*int(n/2)
    for i in range(int(n/2)):
        print(st1)
        print(st2)

else:
    b=n-1
    st1=s1*int(b/2)+"c"
    st2=s2*int(b/2)+"."
    for i in range(int(b/2)):
        print(st1)
        print(st2)
    print(st1)