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(n*n//2)
    for x in range(n//2):
        for x in range(n//2):
            print("C.", end = "")
        print("")
        for x in range(n//2):
            print(".C", end = "")
        print("")
else:
    print((((n//2) + 1)*((n//2) + 1)) + ((n//2)*(n//2)))
    for x in range(n//2):
        for x in range(n//2):
            print("C.", end = "")
        print("C")
        for x in range(n//2):
            print(".C", end = "")
        print(".")
    for x in range(n//2):
        print("C.", end = "")
    print("C")