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).

def main():
    n = int(input())
    c = 0
    data =[]
    for i in range(n):
        res = ""
        for j in range(n):
            if i%2==0:
                res+="C" if j%2==0 else "."
                if j%2==0:
                    c+=1
            else:
                res += "C" if j % 2 != 0 else "."
                if j%2!=0:
                    c+=1
        data.append(res)
    print(c)
    for l in data:
        print(l)




if __name__ == "__main__":
    main()
