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

class Dijkstra {
public:
    struct edge { long long v, dist; };

    struct state {
        long long v, cost;
        bool operator>(const state s) const { return cost > s.cost; }
    };

    const long long INF = (1LL << 60);
    long long N;
    vector< vector<edge> > E;

    Dijkstra(long long n): N(n), E(n) {}

    //有効グラフの時はこっち。u→vに距離dで結ぶ
    void add_directed_edge(long long u, long long v, long long d) {
        E[u].push_back((edge) { v, d });
    }

    //無向グラフの時はこっち。uとvを双方向に距離dで結ぶ
    void add_undirected_edge(long long u, long long v, long long d) {
        E[u].push_back((edge) { v, d });
        E[v].push_back((edge) { u, d });
    }

    //Sを始点として、他の頂点への最短経路を探す
    vector<long long> shortest_path(long long S) {
        vector<long long> dp(E.size(), INF);
        priority_queue<state, vector<state>, greater<state> > q;
        q.push((state) { S, 0 });
        while(!q.empty()) {
            long long v = q.top().v, cost = q.top().cost;
            q.pop();
            if(dp[v] <= cost) continue;
            dp[v] = cost;
            for(int i=0;i < E[v].size() ; i++) {
            long long nv = E[v][i].v, ncost = cost + E[v][i].dist;
            if(dp[nv] > ncost) q.push((state) { nv, ncost });
            }
        }
        return dp;
    }
};

 
signed main(){
    ios::sync_with_stdio(false);
	cin.tie(0);

    int n,m,p,q,t;
    cin>>n>>m>>p>>q>>t;
    p--,q--;
    Dijkstra dij(n);
    for(int i=0;i<m;i++){
        int a,b,c;
        cin>>a>>b>>c;
        dij.add_undirected_edge(--a,--b,c);
    }
    vector<ll> P=dij.shortest_path(p),Q=dij.shortest_path(q),v=dij.shortest_path(0);
    ll dist = v[p] + P[q] + Q[0];
    if(dist<=t){
        cout<<t<<endl;
        return 0;
    }
    dist = max(v[p],v[q]);
    if(2*(dist)>t){
        cout<<-1<<endl;
        return 0;
    }
    ll ans=0;
    for(int i=0;i<n;i++){
        for(int j=0;j<n;j++){
            dist = v[i] + max(P[i] + P[j],Q[i] + Q[j]) + v[j];
            if(dist<=t){
                ans = max(ans, t-max(P[i] + P[j],Q[i] + Q[j]));
            } 
        }
    }
    cout<<ans<<endl;

    
}