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).
# CodeForces : Coder
if __name__ == "__main__":
    n = int(input())
    if n%2==0:
        print((n*n)/2)
    else:
        print((n*n+1)/2)
    arr1 = []
    for i in range(n):
        arr2 = []
        for j in range(n):
            if (i + j) % 2 == 0:
                arr2.append("C")
            else:
                arr2.append(".")
        arr1.append(arr2)
    for n in arr1:
        print("".join(n))