doWeirdStuffWithBinaryStrings

	public static String doStuff(int n, int j, int k) {
		String s = formN(n);
		return s.substring(j, k+1);
		
	}


	private static String formN(int n) {
		StringBuilder sb = new StringBuilder("");
		for(int i = 0; i<=n; i++){
			sb.append(Integer.toBinaryString(i));
		}
		return sb.toString();
	}


	public static void main(String [] args) {
		System.out.println(doStuff(5, 3, 6));
	}