#include <iostream>
#include <vector>
#include <queue>
#include <tuple>
#include <limits>

template <class T>
using MinHeap = std::priority_queue<T, std::vector<T>, std::greater<T>>;

template <class Cost = int>
struct Edge {
    int src, dst;
    Cost cost;
    Edge(int src = -1, int dst = -1, Cost cost = 1)
        : src(src), dst(dst), cost(cost){};

    bool operator<(const Edge<Cost>& e) const { return this->cost < e.cost; }
    bool operator>(const Edge<Cost>& e) const { return this->cost > e.cost; }
};

template <class Cost = int>
struct Graph {
    std::vector<std::vector<Edge<Cost>>> graph;

    Graph(int n = 0) : graph(n) {}

    void span(bool direct, int src, int dst, Cost cost = 1) {
        graph[src].emplace_back(src, dst, cost);
        if (!direct) graph[dst].emplace_back(dst, src, cost);
    }

    std::vector<Edge<Cost>>& operator[](int v) { return graph[v]; }
    std::vector<Edge<Cost>> operator[](int v) const { return graph[v]; }

    int size() const { return graph.size(); }
};

template <class Cost>
std::vector<Cost> dijkstra(const Graph<Cost>& graph, int s) {
    constexpr Cost INF = std::numeric_limits<Cost>::max() / 10;

    std::vector<Cost> dist(graph.size(), INF);
    dist[s] = 0;
    MinHeap<std::pair<Cost, int>> que;
    que.emplace(0, s);

    while (!que.empty()) {
        int v;
        Cost d;
        std::tie(d, v) = que.top();
        que.pop();
        if (d > dist[v]) continue;

        for (const auto& e : graph[v]) {
            if (dist[e.dst] <= dist[v] + e.cost) continue;
            dist[e.dst] = dist[v] + e.cost;
            que.emplace(dist[e.dst], e.dst);
        }
    }

    return dist;
}

using lint = long long;

void solve() {
    int n, m, p, q;
    lint t;
    std::cin >> n >> m >> p >> q >> t;
    --p, --q;

    Graph<lint> graph(n);
    while (m--) {
        int u, v;
        lint c;
        std::cin >> u >> v >> c;
        graph.span(false, --u, --v, c);
    }

    auto ds0 = dijkstra(graph, 0),
         dsp = dijkstra(graph, p),
         dsq = dijkstra(graph, q);

    lint ans = t + 1;
    if (ds0[p] + dsp[q] + dsq[0] <= t) ans = 0;

    for (int u = 0; u < n; ++u) {
        for (int v = 0; v < n; ++v) {
            lint pcost = std::max(dsp[u] + dsp[v],
                                  dsq[u] + dsq[v]);
            lint tcost = ds0[u] + ds0[v];

            if (pcost + tcost > t) continue;
            ans = std::min(ans, pcost);
        }
    }

    std::cout << t - ans << std::endl;
}

int main() {
    std::cin.tie(nullptr);
    std::ios::sync_with_stdio(false);

    solve();

    return 0;
}