Problem: Let's define a string <x> as an opening tag, where x is any small letter of the Latin alphabet. Each opening tag matches a closing tag of the type </x>, where x is the same letter.

Tegs can be nested into each other: in this case one opening and closing tag pair is located inside another pair.

Let's define the notion of a XML-text: 

  * an empty string is a XML-text
  * if s is a XML-text, then s'=<a>+s+</a> also is a XML-text, where a is any small Latin letter 
  * if s1, s2 are XML-texts, then s1+s2 also is a XML-text



You are given a XML-text (it is guaranteed that the text is valid), your task is to print in the following form: 

  * each tag (opening and closing) is located on a single line 
  * print before the tag 2 * h spaces, where h is the level of the tag's nestedness. 

Input

The input data consists on the only non-empty string — the XML-text, its length does not exceed 1000 characters. It is guaranteed that the text is valid. The text contains no spaces.

Output

Print the given XML-text according to the above-given rules.

Examples

Input

&lt;a&gt;&lt;b&gt;&lt;c&gt;&lt;/c&gt;&lt;/b&gt;&lt;/a&gt;


Output

&lt;a&gt;
  &lt;b&gt;
    &lt;c&gt;
    &lt;/c&gt;
  &lt;/b&gt;
&lt;/a&gt;


Input

&lt;a&gt;&lt;b&gt;&lt;/b&gt;&lt;d&gt;&lt;c&gt;&lt;/c&gt;&lt;/d&gt;&lt;/a&gt;


Output

&lt;a&gt;
  &lt;b&gt;
  &lt;/b&gt;
  &lt;d&gt;
    &lt;c&gt;
    &lt;/c&gt;
  &lt;/d&gt;
&lt;/a&gt;

Solution (in JAVA):

Solution:
import java.util.Scanner;
public class Bt2 {
	static Scanner in = new Scanner(System.in);

	static int ni() {
		return in.nextInt();
	}

	static String nl() {
		return in.nextLine();
	}
	
	static int i;
	static void process(String t, int l) {
		for (int j = 0; j < 2*l; j++) System.out.print(' ');
		System.out.println(t.substring(i, i+3));
		i+=3;
		while (t.charAt(i+1)!='/') process(t, l+1);
		for (int j = 0; j < 2*l; j++) System.out.print(' ');
		System.out.println(t.substring(i, i+4));
		i+=4;
	}

	public static void main(String[] args) {
		String s = nl();
		if (s.isEmpty()) {
			System.out.println();
			return;
		}
		i = 0;
		while (i < s.length())
		process(s, 0);
	}
}