#include <bits/stdc++.h>
using namespace std;
int main() {
  string s;
  cin >> s;
  long long i = 1;
  long long k = 0;
  long long MAXN = 1e5;
  long long ki[MAXN];
  fill(ki, ki + MAXN, 0);
  while (i < s.length()) {
    if (s[i] == '/') {
      k -= 2;
      for (long long j = 0; j < k; j++) {
        cout << " ";
      }
      cout << s[i - 1] << s[i] << s[i + 1] << s[i + 2];
      i += 4;
      if (i < s.length()) cout << endl;
    } else {
      for (int j = 0; j < k; j++) {
        cout << " ";
      }
      cout << s[i - 1] << s[i] << s[i + 1];
      i += 3;
      k += 2;
      if (i < s.length()) cout << endl;
    }
  }
  return 0;
}
