class RandUtil {

	public static String nextAlphabetic(int characters) {
		StringBuffer buffer = new StringBuffer();
		for (int i = 0; i < characters; i++) {
			if (nextBoolean())
				buffer.append((char) nextInt('A', 'Z'));
			else
				buffer.append((char) nextInt('a', 'z'));
		}

		return buffer.toString();
	}

	private  RandUtil();

}