package chelper;

import java.util.ArrayList;
import java.util.Collection;
import java.util.Collections;
import java.util.Comparator;
import java.util.List;
import java.util.Map;
import java.util.SortedMap;
import java.util.TreeMap;

import io.InputReader;
import io.OutputWriter;
import misc.SimpleSavingChelperSolution;


public class B extends SimpleSavingChelperSolution {

  public void solve(int testNumber, InputReader in, OutputWriter out) {
    wrapSolve(testNumber, in, out);
  }

  @Override
  public void solve(int testNumber) {
    int n = in.nextInt();
//    int[] a = in.nextIntArray(n);

    List<int[]> a = new ArrayList<>();

    for (int i = 0; i < n; i++) {
      int t = in.nextInt();

      a.add(new int[]{t, i});
    }

    a.sort((o1, o2) -> Integer.compare(o1[0], o2[0]));
    Collections.reverse(a);

    int max = -1;
    int c = 0;

    TreeMap<Integer, Integer> map = new TreeMap<>();
    int[] b = new int[n];

    List<List<Integer>> lists = new ArrayList<>();

    for (int[] i : a) {
      int element = i[0];
      int index = i[1];

      Integer next = map.ceilingKey(index);

      if (next == null) {
        map.put(index, c);

        lists.add(new ArrayList<>());
        lists.get(c).add(element);

        c++;

        continue;
      }

      int t = map.get(next);
      lists.get(t).add(element);
      map.put(index, t);
      map.remove(next);
    }

    for (List<Integer> list : lists) {
      Collections.sort(list);

      for (Integer integer : list) {
        out.print(integer + " ");
      }
      out.println();
    }
  }
}