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 PYTHON3):

Solution:
from bisect import insort,bisect_right,bisect_left
from sys import stdout, stdin, setrecursionlimit
from heapq import heappush, heappop, heapify 
from io import BytesIO, IOBase
from collections import *
from itertools import *
from random import * 
from string import *
from queue import *
from math import *
from re import *
from os import *

# sqrt,ceil,floor,factorial,gcd,log2,log10,comb

####################################---fast-input-output----#########################################


class FastIO(IOBase):
    newlines = 0

    def __init__(self, file):
        self._fd = file.fileno()
        self.buffer = BytesIO()
        self.writable = "x" in file.mode or "r" not in file.mode
        self.write = self.buffer.write if self.writable else None

    def read(self):
        while True:
            b = read(self._fd, max(fstat(self._fd).st_size, 8192))
            if not b:
                break
            ptr = self.buffer.tell()
            self.buffer.seek(0, 2), self.buffer.write(b), self.buffer.seek(ptr)
        self.newlines = 0
        return self.buffer.read()

    def readline(self):
        while self.newlines == 0:
            b = read(self._fd, max(fstat(self._fd).st_size, 8192))
            self.newlines = b.count(b"\n") + (not b)
            ptr = self.buffer.tell()
            self.buffer.seek(0, 2), self.buffer.write(b), self.buffer.seek(ptr)
        self.newlines -= 1
        return self.buffer.readline()

    def flush(self):
        if self.writable:
            write(self._fd, self.buffer.getvalue())
            self.buffer.truncate(0), self.buffer.seek(0)


class IOWrapper(IOBase):
    def __init__(self, file):
        self.buffer = FastIO(file)
        self.flush = self.buffer.flush
        self.writable = self.buffer.writable
        self.write = lambda s: self.buffer.write(s.encode("ascii"))
        self.read = lambda: self.buffer.read().decode("ascii")
        self.readline = lambda: self.buffer.readline().decode("ascii")


stdin, stdout = IOWrapper(stdin), IOWrapper(stdout)
graph, mod, szzz =  {}, 10**9 + 7, lambda: sorted(zzz())
def getStr(): return input()
def getInt(): return int(input())
def listStr(): return list(input())
def getStrs(): return input().split()
def isInt(s): return '0' <= s[0] <= '9'
def input(): return stdin.readline().strip()
def zzz(): return [int(i) for i in input().split()]
def output(answer, end='\n'): stdout.write(str(answer) + end)
def lcd(xnum1, xnum2): return (xnum1 * xnum2 // gcd(xnum1, xnum2))


def getPrimes(N = 10**5):
    SN = int(sqrt(N))
    sieve = [i for i in range(N+1)]
    sieve[1] = 0
    for i in sieve:
        if i > SN:
            break
        if i == 0:
            continue
        for j in range(2*i, N+1, i):
            sieve[j] = 0
    prime = [i for i in range(N+1) if sieve[i] != 0] 
    return prime
def primeFactor(n,prime=getPrimes()):
    lst = []
    mx=int(sqrt(n))+1
    for i in prime:
        if i>mx:break
        while n%i==0:
            lst.append(i)
            n//=i
    if n>1:
        lst.append(n)
    return lst    

dx = [-1, 1, 0, 0, 1, -1, 1, -1]
dy = [0, 0, 1, -1, 1, -1, -1, 1]
daysInMounth = [31, 28, 31, 30, 31, 30, 31, 31, 30, 31, 30, 31]


#################################################---Some Rule For Me To Follow---#################################
"""
    --instants of Reading problem continuously try to understand them.

    --Try & again try, maybe you're just one statement away!


"""
##################################################---START-CODING---###############################################


lst= getStr()


arr = []

ch=''

for i in lst:

    if i=='>':
        arr.append(ch+'>')
        ch=''
    else:
        ch+=i


que=deque()

for i in arr:
    if i[:2]=="</":
        x=que.pop()
        sp=" "*(2*len(que))
        print(sp+"</"+x[1:])
    else:
        sp=" "*(2*len(que))
        print(sp+i)
        que.append(i)