public static void main(String[]args){
        Scanner k = new Scanner(System.in);
        String abc = "ABCDEFGHIJ";
        String ab = "abcdefghij";
        abc.equals(ab);
        System.out.println("Please enter the attack location:");

            while (!k.hasNext("[A-J a-j]+[0-9]")) {
                System.out.println("Wrong");
                k.next();
            }

            String location = k.next();
            char row = location.charAt(0);
            int num = (int) location.charAt(1);
            System.out.println(abc.charAt(row));
}
}