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).
def coder():
    a=int(input())
    ans=0
    s=''
    for i in range(a):
        for j in range(a):
            if (i+j)%2==0:
                s+='C'
                ans+=1
            else:
                s+='.'
        s+='\n'
    print(str(ans)+'\n'+s)
coder()