#include <iostream>
#include <vector>

using namespace std;

vector<int> fe;

int llegeix() {
  char c;
  cin >> c;
  if (c == '0') return -1;

  int k = fe.size();
  fe.push_back(42);

  //int aux = llegeix();
  fe[k] = llegeix();
  //fe[k] = aux;

  return k;
}

int main()
{
  llegeix();

  for (int i = 0; i < fe.size(); ++i) cout << fe[i] << endl;
  
  return 0;
}