using System;
using System.Collections.Generic;

namespace ConsoleApp2
{
    class Program
    {
        static void Main(string[] args)
        {
            Solution sol = new Solution();
            Console.WriteLine(sol.solution(5, new int[,] { { 0,1,1 }, { 3,4,1 }, { 1,2,2}, { 2,3,4 }}));
        }
    }

    public class Solution
    {
        public class Node : IComparable<Node>
        {
            public int cur;
            public int next;
            public int dis;

            public Node(int cur, int next, int dis)
            {
                this.cur = cur;
                this.next = next;
                this.dis = dis;
            }

            public int CompareTo(Node other)
            {
                if (dis < other.dis)
                {
                    return -1;
                }
                else if (dis > other.dis)
                {
                    return 1;
                }
                else
                    return 0;
            }
        }
        public int GetParent(int[] table, int adr)
        {
            if (table[adr] == adr) return adr;
            return table[adr] = GetParent(table, table[adr]);
        }

        public void SetParent(int[] table,int a, int b)
        {
            a = GetParent(table, a);
            b = GetParent(table, b);

            int min = Math.Min(a, b);
            table[a] = table[b] = min;
        }
        public int solution(int n, int[,] costs)
        {
            int answer = 0;
            int[] table = new int[n];
            List<Node> nodeList = new List<Node>();

            for (int i = 0; i < n; i++)
            {
                table[i] = i;
            }
            for (int i = 0; i < costs.GetLength(0); i++)
            {
                nodeList.Add(new Node(costs[i, 0], costs[i, 1], costs[i, 2]));
            }
            nodeList.Sort();

            for (int i = 0; i < nodeList.Count; i++)
            {
                if (table[nodeList[i].cur] != table[nodeList[i].next])
                {
                    answer += nodeList[i].dis;

                    SetParent(table, nodeList[i].cur, nodeList[i].next);
                    //int min = Math.Min(table[nodeList[i].cur], table[nodeList[i].next]);
                    //int max = Math.Max(table[nodeList[i].cur], table[nodeList[i].next]);
                    //table[nodeList[i].cur] = table[nodeList[i].next] = min;

                    //for (int j = 0; j < table.Length; j++)
                    //{
                    //    if (table[j] == max)
                    //    {
                    //        table[j] = min;
                    //    }
                    //}
                }
            }

            return answer;
        }
    }
}