#include <bits/stdc++.h>
using namespace std;

using P = pair<long long, int>;
using Graph = vector<vector<P>>;

void dijkstra(const Graph &G, vector<long long> &dist, int s) {
    priority_queue<P, vector<P>, greater<P>> que;
    dist[s] = 0;
    que.emplace(dist[s], s);

    while (!que.empty()){
        auto p = que.top();
        que.pop();
        int v = p.second;
        if (dist[v] < p.first) continue;

        for (auto np : G[v]) {
            auto nv = np.second;
            auto dis = np.first;
            if (dist[nv] > dist[v] + dis) {
                dist[nv] = dist[v] + dis;
                que.emplace(dist[nv], nv);
            }
        }
    }
}

int main() {
    int N, M, P, Q;
    long long T;
    cin >> N >> M >> P >> Q >> T;
    P--; Q--;
    Graph G(N);
    for (int i = 0; i < M; i++) {
        int a, b;
        long long c;
        cin >> a >> b >> c;
        a--; b--;
        G[a].emplace_back(c, b);
        G[b].emplace_back(c, a);
    }

    vector<long long> dist(N, 1LL << 60), distP(N, 1LL << 60), distQ(N, 1LL << 60);
    dijkstra(G, dist, 0);
    dijkstra(G, distP, P);
    dijkstra(G, distQ, Q);

    if (dist[P] + dist[Q] + distP[Q] <= T) {
        cout << T << endl;
        return 0;
    }

    long long ans = -1;
    for (int i = 0; i < N; i++) {
        for (int j = 0; j < N; j++) {
            if (max(dist[i] + distP[i] + distP[j] + dist[j], dist[i] + distQ[i] + distQ[j] + dist[j]) > T) continue;
            ans = max(ans, T - max(distP[i] + distP[j], distQ[i] + distQ[j]));
        }
    }

    cout << ans << endl;
}