JaeHyeonKim19

import java.io.*;
import java.util.*;

class Edge {
	int to;
	int distance;
	Edge(int to, int distance){
		this.to = to;
		this.distance = distance;
	}
}

public class Main {
	static ArrayList<Edge> [] al;
	static boolean [] visited;
	static int max = 0;
	static int firstNode;

	static void dfs(int curNode, int acc) {
		boolean isEnd = true;
		visited[curNode] = true;
		for(int i = 0; i < al[curNode].size(); i++) {
			Edge temp = al[curNode].get(i);
			if(!visited[temp.to]) {
				isEnd = false;
				visited[temp.to] = true;
				dfs(temp.to, acc+temp.distance);
			}
		}
		if(isEnd) {
			if(acc > max) {
				max = acc;
				firstNode = curNode;
			}
		}
	}

	public static void main(String[] args) throws IOException{
		BufferedReader br = new BufferedReader(new InputStreamReader(System.in));
		int v = Integer.parseInt(br.readLine());
		al = (ArrayList<Edge>[])new ArrayList[v+1];
		visited = new boolean[v+1];
		for(int i = 0; i < v+1; i++) {
			al[i] = new ArrayList<Edge>();
		}
		StringTokenizer st = new StringTokenizer(" ");
		for(int i = 0; i < v; i++) {
			st = new StringTokenizer(br.readLine());
			int nodeNum = Integer.parseInt(st.nextToken());
			int to = Integer.parseInt(st.nextToken());
			while(to != -1) {
				int distance = Integer.parseInt(st.nextToken());
				al[nodeNum].add(new Edge(to, distance));
				to = Integer.parseInt(st.nextToken());
			}
		}
		dfs(1, 0);
		max = 0;
		for(int i = 0; i < v+1; i++) {
			visited[i] = false;
		}
		dfs(firstNode, 0);
		System.out.print(max);
	}
}