class BaseCalculator {
    public static void main(String[] args) {
        if(verifyInput(args)) {
            System.out.println(calculateBase(returnBase(args),returnNumber(args)));
            String[] test = returnNumber(args);
        } else {
            System.out.println("Error, Your input could not be validated");
        }
    }

    private static int findBase(String[] args) {
        int size = args.length;
        String base;
        for(int i = 0; i < size; i++) {
            if (args[i].equals("-b")) {
                return i + 1;
            }
        }
        return 0;
    }
    private static int returnBase(String[] args) {
        String fReturn;
        if (findBase(args) < 1) {
            return 2;
        }
        return Integer.parseInt(args[findBase(args)]);
    }

    public static int calculateBase(int b, String[] args) {
        int count = 0;
        int result = 0;
        for(int i = 0; i < args.length; i++) {
            if(!args[i].equals("null")) {
                count++;
            }
        }
        //System.out.print(count);
        for(int i = 0; i < args.length; i++) {
            if(!args[i].equals("null")) {
                result += Integer.parseInt(args[i]) * (Math.pow(b,count-1));
                count--;
            }
        }
        return result;
    }

    private static String[] returnNumber(String[] args) {
        int base = findBase(args);
        String[] result = args;
        if (base > 1) {
            for (int i = base - 1; i < args.length; i++) {
                result[i] = "null";
            }
        } else if(base != 0) {
            result[0] = "null";
            result[1] = "null";
        }
        return args;

    }

    protected static boolean verifyInput(String[] args) {
        if(returnBase(args) < 2) {
            return false;
        }
        if(findBase(args) < args.length - 1 && findBase(args) > 1) {
            return false;
        }
        return true;
    }
}