#include <bits/stdc++.h>
using namespace std;
int main() {
  string s;
  int i, d;
  cin >> s;
  for (i = 0, d = 0; i < s.size(); i++) {
    if (s[i + 1] == '/') d -= 2;
    cout << string(d, ' ');
    if (s[i + 1] != '/') d += 2;
    for (;; i++) {
      cout << s[i];
      if (s[i] == '>') break;
    }
    cout << endl;
  }
  return 0;
}
