class Provisioner {

    String rot13(String text) {
        StringBuilder sb = new StringBuilder(text.length());
        for (int i = 0; i < text.length(); i++) {
            char c = text.charAt(i);
            if ((c >= 'a' && c <= 'm') || (c >= 'A' && c <= 'M')) {
                sb.append((char) (c + 13));
            } else if ((c >= 'n' && c <= 'z') || (c >= 'N' && c <= 'Z')) {
                sb.append((char) (c - 13));
            } else {
                sb.append(c);
            }
        }
        return sb.toString();
    }

    protected  Provisioner();

}