class Edge {
        int to, weight;

        public Edge(int to, int weight) {
            this.to = to;
            this.weight = weight;
        }
    }

     class Node implements Comparable<Node> {
        int id;
        long cost;

        public Node(int id, long cost) {
            this.id = id;
            this.cost = cost;
        }

        @Override
        public int compareTo(Node other) {
            return Long.compare(this.cost, other.cost);
        }
    }

     class Result {
        public static void getCost(int gNodes, List<Integer> gFrom, List<Integer> gTo, List<Integer> gWeight) {
            List<List<Edge>> graph = new ArrayList<>(gNodes + 1);
            for (int i = 0; i <= gNodes; i++) {
                graph.add(new ArrayList<>());
            }

            for (int i = 0; i < gFrom.size(); i++) {
                int from = gFrom.get(i);
                int to = gTo.get(i);
                int weight = gWeight.get(i);
                graph.get(from).add(new Edge(to, weight));
                graph.get(to).add(new Edge(from, weight));
            }

            long[] dist = new long[gNodes + 1];
            Arrays.fill(dist, Long.MAX_VALUE);
            dist[1] = 0;

            PriorityQueue<Node> pq = new PriorityQueue<>();
            pq.add(new Node(1, 0));

            while (!pq.isEmpty()) {
                Node current = pq.poll();
                int u = current.id;
                long currentCost = current.cost;

                if (currentCost > dist[u]) continue;

                for (Edge edge : graph.get(u)) {
                    int v = edge.to;
                    long newCost = edge.weight;

                    if (currentCost < newCost) {
                        newCost -= currentCost;
                    } else {
                        newCost = 0;
                    }

                    if (dist[u] + newCost < dist[v]) {
                        dist[v] = dist[u] + newCost;
                        pq.add(new Node(v, dist[v]));
                    }
                }
            }

            long result = dist[gNodes];
            if (result == Long.MAX_VALUE) {
                System.out.println("NO PATH EXISTS");
            } else {
                System.out.println(result);
            }
        }
    }