private void printStringsFromSetHelper(char[] n, int k, StringBuilder s){
		if(s.length() == k){
			System.out.println(s.toString());
			return;
		}
		for(int i=0; i<n.length; i++){
			StringBuilder builder = new StringBuilder(s);
			builder.append(n[i]);
			printStringsFromSetHelper(n, k, builder);
		}
	}