#include <algorithm>
#include <iostream>
#include <vector>
#include <queue>
#include <tuple>
using namespace std;

template <typename T>
struct Edge { int src, dst; T cost;
    Edge(int dst, T cost) : src(-1), dst(dst), cost(cost) { }
    Edge(int src, int dst, T cost) : src(src), dst(dst), cost(cost) { }
};
template <typename T> using Edges = vector<Edge<T>>;
template <typename T> using WeightedGraph = vector<Edges<T>>;
template <typename T> using Matrix = vector<vector<T>>;

template <typename T>
vector<T> dijkstra(const WeightedGraph<T> &g, int s) {
    const T INF = numeric_limits<T>::max();
    vector<T> dist(g.size(), INF);
    vector<int> prev(g.size(), -1);
    using Pi = pair<T, int>;
    priority_queue<Pi, vector<Pi>, greater<Pi>> que;
    dist[s] = 0; que.emplace(dist[s], s);
    while (!que.empty()) {
        T cost; int u; tie(cost, u) = que.top(); que.pop();
        if (dist[u] < cost) continue;
        for (auto &e: g[u]) {
            int v = e.dst; T nc = e.cost;
            if (dist[v] <= dist[u] + nc) continue;
            dist[v] = dist[u] + nc; prev[v] = u;
            que.emplace(dist[v], v);
        }
    }
    return dist;
}

int main() {
    int N, M, P, Q, T; cin >> N >> M >> P >> Q >> T; P--, Q--;
    WeightedGraph<long long> g(N);
    while (M--) {
        int a, b, c; cin >> a >> b >> c; a--, b--;
        g[a].emplace_back(b, c);
        g[b].emplace_back(a, c);
    }
    vector<long long> d, p, q;
    d = dijkstra(g, 0);
    p = dijkstra(g, P);
    q = dijkstra(g, Q);
    if (d[P] + p[Q] + q[0] <= T) return cout << T << endl, 0;
    int ans = -1;
    for (int s = 0; s < N; s++) for (int t = 0; t < N; t++) {
        int alone = max(p[s] + p[t], q[s] + q[t]);
        if (d[s] + alone + d[t] <= T) ans = max(ans, T - alone);
    }
    cout << ans << endl;
    return 0;
}