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