/**
 *   @FileName	a.cpp
 *   @Author	kanpurin
 *   @Created	2020.06.14 19:43:30
**/

#include "bits/stdc++.h" 
using namespace std; 
typedef long long ll;




template<typename T>
struct Dijkstra {
private:
    int V;
    struct edge { int to; T cost; };
    vector<vector<edge>> G;
public:
    const T inf = numeric_limits<T>::max();
    
    
    vector<T> d; 
    Dijkstra(int V) : V(V) {
        G.resize(V);
    }
    
    
    void add_edge(int from, int to, T weight, bool directed = false) {
        G[from].push_back({to,weight});
        if (!directed) G[to].push_back({from,weight});
    }
    void build(int s) {
        d.assign(V, inf); 
        typedef tuple<T, int> P; 
        priority_queue<P, vector<P>, greater<P>> pq;
        d[s] = 0; 
        pq.push(P(d[s], s)); 
        while (!pq.empty()) {
            P p = pq.top(); pq.pop();
            int v = get<1>(p);
            
            if (d[v] < get<0>(p)) continue; 
            for (const edge &e : G[v])
            {
                
                if (d[e.to] > d[v] + e.cost) {
                    d[e.to] = d[v] + e.cost;
                    pq.push(P(d[e.to], e.to));
                }
            }
        }
    }
};
int main() {
    int n,m,p,q,t;cin >> n >> m >> p >> q >> t;
    p--;q--;
    Dijkstra<ll> g1(n),gp(n),gq(n);
    for (int i = 0; i < m; i++) {
        int u,v,c;cin >> u >> v >> c;
        u--;v--;
        g1.add_edge(u,v,c);
        gp.add_edge(u,v,c);
        gq.add_edge(u,v,c);
    }
    g1.build(0);
    gp.build(p);
    gq.build(q);
    if (g1.d[p] + gp.d[q] + gq.d[0] <= t) {
        cout << t << endl;
        return 0;
    }
    ll ans = -1;
    for (int i = 0; i < n; i++) {
        ll t1 = g1.d[i];
        ll tp = gp.d[i];
        ll tq = gq.d[i];
        ll aaa = max(tp,tq);
        if (2 * t1 + 2 * aaa > t) continue;
        ans = max(ans,t - 2 * aaa);
    }
    cout << ans << endl;
    return 0;
}