#include <bits/stdc++.h>
using namespace std;
template <typename T, typename U>
std::pair<T, U> operator+(const std::pair<T, U>& l, const std::pair<T, U>& r) {
  return {l.first + r.first, l.second + r.second};
}
typedef void (*callback_function)(void);
const long long INF64 = 1e18;
const long long INF32 = 1e9;
const long long MOD = 1e9 + 7;
const long double PI = acos(-1.0L);
const long double EPS = static_cast<long double>(1e-9);
int main() {
  ios_base::sync_with_stdio(false);
  cin.tie();
  {
    string s;
    cin >> s;
    long long space = 0, close;
    for (long long i = (0); i < (s.length()); i++) {
      close = (s[i + 1] == '/' ? 1 : 0);
      if (close) space -= 2;
      for (long long j = (0); j < (space); j++) cout << ' ';
      if (!close) space += 2;
      cout << s.substr(i, close ? 4 : 3) << endl;
      i += 2 + close;
    }
  }
  return 0;
}
