using System using System Collections Generic using System Linq using

using System;
using System.Collections.Generic;
using System.Linq;
using System.Text;
using System.Threading.Tasks;

namespace ConsoleApplication8
{
  class Arcs
  {
    int[] heads;
    int[] destination;
    int[] nextArc;

    public Arcs(int n, int m, int[] from, int[] to)
    {
      heads = new int[n];
      destination = new int[m];
      nextArc = new int[m];

      for(int i = 0; i < heads.Length; ++i)
      {
        heads[i] = -1;
      }
      
      for(int i = 0; i < m; ++i)
      {
        AddArc(from[i], to[i], i);
      }
    }

    public void AddArc(int from, int to, int i)
    {
      nextArc[i] = heads[from];
      destination[i] = to;
      heads[from] = i; 
    }

    public void viewArcs(int from)
    {
      int j;
      for(int i = heads[from]; i != -1; i = nextArc[i])
      {
        j = destination[i];
        Console.Write("{0} ", j);
      }
    }
  }
  class Program
  {
    static void Main(string[] args)
    {
      int n = 6, m = 5;
      int[] from = new int []{ 0,0,0,0,0 };
      int[] to = new int []{ 1, 2, 3, 4, 5 };
      Arcs arcs = new Arcs(n,m, from, to);

      arcs.viewArcs(0);
    }
  }
}