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())
l=[]
cnt=0
for io in range(0,n):
                if io%2==0:
                                s="C"
                else:
                                s="."
                for hj in range(0,n-1):
                                if s[len(s)-1]=="C":
                                                s=s+"."
                                else:
                                                s=s+"C"
                l.append(s)
                cnt=cnt+s.count("C")
print(cnt)
for bn in range(0,len(l)):
                print(l[bn])
