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*n))
else:
    print(int(int(n/2)*n+int(n/2+1)))
if(n%2==0):
    for i in range(int(n/2)):
        for j in range(int(n/2)):
            print("C.", end='')
        print()
        for j in range(int(n/2)):
            print(".C", end='')
        print()
else:
    for i in range(int(n/2)):
        for j in range(int(n/2)):
            print("C.", end='')
        print("C", end='')
        print()
        for j in range(int(n/2)):
            print(".C", end='')
        print(".", end='')
        print()
for j in range(int(n/2)):
            print("C.", end='')
print("C", end='')
print()
