public class Vector
{
    public Node from;
    public Node to;
    public float weight;
    public Vector(Node from, Node to, float weight)
    {
        this.from = from;
        this.to = to;
        this.weight = weight;
    }
}

public class Node
{
    private int _value;
    private HashSet<Vector> _children;

    public Node(int v)
    {
        _value = v;
        _children = new HashSet<Vector>();
    }

    public int value()
    {
        return _value;
    }

    public void addChild(Node n , float weight)
    {
        Vector a = new Vector(this, n, weight);
        _children.Add(a);
    }

    public List<Vector> children()
    {
        return _children.ToList();
    }
}

public class Graph
{
    private Dictionary<int, Node> nodes;
    public Graph()
    {
        nodes = new Dictionary<int, Node>();
    }

    public int create()
    {
        Node n = new Node(nodes.Count + 1);
        nodes.Add(n.value(), n);
        return n.value();
    }

    public void connect(int father, int child, float weight)
    {
        Node f, c;
        nodes.TryGetValue(father, out f);
        nodes.TryGetValue(child, out c);
        f.addChild(c, weight);
        c.addChild(f, weight);
    }

    public Graph Kruskal()
    {

    }