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#include <bits/stdc++.h>
using namespace std;
typedef long long int ll;
#define endl "\n"
 
const double PI = 3.14159265358979;
const ll INF =  1e9 + 7;
const ll MOD = 1e9 + 7;
const ll nax = 2505;
const int LOG = 25;


int dijkstra(int start, int end, int capacity, int n, vector<pair<int, int> > adj[], vector<int> &prices) {

    vector<vector<int> > dist(n + 1, vector<int> (capacity + 1, INF));
    vector<vector<bool> > vis(n + 1, vector<bool> (capacity + 1, false));
    priority_queue<pair<int, pair<int, int> > > pq;

    dist[start][0] = 0;
    pq.push({-dist[start][0], {start, 0}});

    while(!pq.empty()) {
        auto topElement = pq.top(); pq.pop();
        int currCost = -topElement.first;
        int currNode = topElement.second.first;
        int currFuel = topElement.second.second;

        if (vis[currNode][currFuel]) continue;
        vis[currNode][currFuel] = true;


        // 1. go to a neighbour using a route
        for (auto &v: adj[currNode]) {
            int neigh = v.first;
            int pathLength = v.second;

            if (currFuel >= pathLength) {
                if (dist[neigh][currFuel - pathLength] > currCost + 0) {
                    dist[neigh][currFuel - pathLength] = currCost + 0;
                    pq.push({-dist[neigh][currFuel - pathLength], {neigh, currFuel - pathLength}});
                }
            }
        }


        // 2. refill by 1 unit at currNode
        if (currFuel < capacity) {
            if (dist[currNode][currFuel + 1] > currCost + prices[currNode]) {
                dist[currNode][currFuel + 1] = currCost + prices[currNode];
                pq.push({-dist[currNode][currFuel + 1], {currNode, currFuel + 1}});
            }
        } 
    }

    int ans = INF;
    for (int i = 0; i <= capacity; i++) {
        ans = min(ans, dist[end][i]);
    }
    return ans;
}

void solve() {
    int n, m;
    cin >> n >> m;

    vector<pair<int, int> > adj[n + 1];
    for (int i = 1; i <= m; i++) {
        int u, v, d;
        cin >> u >> v >> d;
        adj[u].push_back({v, d});
        adj[v].push_back({u, d});
    }

    vector<int> prices(n + 1);
    for (int i = 1; i <= n; i++) {
        cin >> prices[i];
    }

    int start, end, capacity;
    cin >> start >> end >> capacity;

    int minCost = dijkstra(start, end, capacity, n, adj, prices);
    cout << minCost;
}

signed main() {
    ios_base::sync_with_stdio(false);
    cin.tie(nullptr);
    cout.tie(nullptr);

    // int t; cin >> t; while(t--)
    solve();
    return 0;
}
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