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).
 sa=int(input())
print(int((sa**2+1)/2))
for x in range(sa):
    newchain=''
    if x%2==0:
        while len(newchain)<sa:
            if len(newchain)<sa:
                newchain+='C'
            if len(newchain)<sa:
                newchain+='.'
    if x%2==1:
        while len(newchain)<sa:
            if len(newchain)<sa:
                newchain+='.'
            if len(newchain)<sa:
                newchain+='C'

    print(newchain)