#include <vector>
#include <iostream>
#include <cstdio>
#include <cstdlib>
using namespace std;

struct TreeNode {
    int val;
    TreeNode *left;
    TreeNode *right;
    TreeNode() : val(0), left(nullptr), right(nullptr) {}
    TreeNode(int x) : val(x), left(nullptr), right(nullptr) {}
    TreeNode(int x, TreeNode *left, TreeNode *right) : val(x), left(left), right(right) {}
};

class Solution {
public:
    vector <vector <int> > verticalTraversal(TreeNode* root);
};


vector <vector <int> > Solution::verticalTraversal(TreeNode* root)
{
  vector < vector <int> > rv;
  return rv;
}

int main()
{
  vector <TreeNode *> N;
  TreeNode *t;
  int n;
  int i, l, r, j;
  vector < vector <int> > rv;
  Solution s;

  while (cin >> n) {          /* Read in the vals of the tree.  If a val is -1, the node is NULL */
    if (n >= 0) {
      t = new TreeNode(n);
      N.push_back(t);
    } else {
      N.push_back(nullptr);
    }
  }

  for (i = 0; i < N.size(); i++) {   /* Set up the pointers of the tree. */
    if (N[i] != nullptr) {
      l = 2*i + 1;
      if (l < N.size()) N[i]->left = N[l];
      l++;
      if (l < N.size()) N[i]->right = N[l];
    }
  }

  rv = s.verticalTraversal(N[0]);         /* Call verticalTraversal on the root */

  for (i = 0; i < rv.size(); i++) {    // Print out the return value - each vector on its own line.
    for (j = 0; j < rv[i].size(); j++) printf("%d ", rv[i][j]);
    printf("\n");
  }
  return 0;
}