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).
# for testCase in range(6):
n = int(input())
print((n*n+1)//2)
for i in range(n):
    for j in range(n):
        if (j&1) == (i&1):
            print('C' ,end='')
        else:
            print('.' ,end='')
    print()
