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())
if n %2 == 0:
    print(int(n**2/2))
    for cont in range(0,n,2):
        s = 'C.'*int(n/2)
        print(s)
        s = '.C'*int(n/2)
        print(s)
else:
    print(int((n**2+1)/2))
    print ('C.'*int(n/2)+'C')
    for cont in range(1,n,2):
        print('.C'*int(n/2)+'.')
        print('C.'*int(n/2)+'C')