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())

row_count = n
if n==1 or n==2:
    print(n)
else:
    print(2+(n-2)*3)

while row_count>0:
    column_count = 0
    while column_count<n :

        if row_count%2==0 and column_count%2==0:
            print("C", end = "")
        elif row_count%2==0 and column_count%2==1:
            print(".", end = "")
        
        elif row_count%2==1 and column_count%2==0:
            print(".", end = "")
        
        elif row_count%2==1 and column_count%2==1:
            print("C", end = "")
        column_count+=1
    print("")
    row_count-=1
        
        