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())
f=0
lst=[]
s=""
cnt=0
for i in range(n):
  for j in range(n):
    if i%2:
       if f:
         s+="C"
         f=0
         cnt+=1
       else:
         s+="."
         f=1
    else:
      if f:
         s+="."
         f=0
      else:
         s+="C"
         f=1
         cnt+=1
  f=0
  lst.append(s)
  s=""
print(cnt)
for i in range(n):
  print(lst[i])




