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())
final=0
even1='C.'
even2='.C'
if n%2==0:
    final=int((n**2)/2)
    print(final)
    for i in range(n):
        if i%2==0:
            print(even1*int(n/2))
        else:
            print(even2*int(n/2))
else:
    final=int((((n**2)+1)/2))
    print(final)
    for i in range(n):
        if i%2==0:
            print(even1*int((n-1)/2)+even1[0])
        else:
            print(even2*int((n-1)/2)+even2[0])