import java.util.ArrayList;
import java.util.Scanner;

public class Main {
    public static int n;
    public static int Max = Integer.MIN_VALUE;
    public static int point = 0;
    public static ArrayList<edge>[] map;
    
    static class edge {
        public int P;
        public int Q;
        public int D;
        
        public edge(int P, int Q, int D) {
            this.P = P;
            this.Q = Q;
            this.D = D;
        }
    }
    
    public void dfs(int start, boolean[] visited, int dis) {
        visited[start] = true;
        for(int i = 0;i < map[start].size();i++) {
            edge temp = map[start].get(i);
            if(visited[temp.Q] == false) {
                dis += temp.D;
                if(dis > Max) {
                    Max = dis;
                    point = temp.Q;
                }
                dfs(temp.Q, visited, dis);
                dis -= temp.D;
            }
        }
    }
    
    public void getResult() {
        boolean[] visited = new boolean[n + 1];
        dfs(1, visited, 0);
        visited = new boolean[n + 1];
        int start = point;
        dfs(start, visited, 0);
        int result = Max * 10 + (Max + 1) * Max / 2;
        System.out.println(result);
    }
    
    @SuppressWarnings("unchecked")
    public static void main(String[] args) {
        Main test = new Main();
        Scanner in = new Scanner(System.in);
        n = in.nextInt();
        map = new ArrayList[n + 1];
        for(int i = 1;i <= n;i++)
            map[i] = new ArrayList<edge>();
        for(int i = 1;i < n;i++) {
            int P = in.nextInt();
            int Q = in.nextInt();
            int D = in.nextInt();
            map[P].add(new edge(P, Q, D));
            map[Q].add(new edge(Q, P, D));
        }
        test.getResult();
    }
}