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

#define int long long

vector<pair<int, int> > graph[2010];

int n, m, p, q, t;
int dist[2010][2010];

void min_dist(int st){
    for(int i = 0;i < n;i++){
        dist[st][i] = LLONG_MAX/4;
    }

    dist[st][st] = 0;
    priority_queue<pair<int, int>, vector<pair<int, int> >, greater<pair<int, int> > > que;
    que.push(make_pair(0, st));

    while(!que.empty()){
        int cost = que.top().first;
        int idx = que.top().second;
        que.pop();

        for(int i = 0;i < graph[idx].size();i++){
            int next = graph[idx][i].first;
            int ncost = graph[idx][i].second + cost;
            if(dist[st][next] > ncost){
                dist[st][next] = ncost;
                que.push(make_pair(ncost, next));
            }
        }
    }

    return;
}

signed main(){

    ios::sync_with_stdio(false);
    cin.tie(0);

    cin >> n >> m >> p >> q >> t;

    p--;
    q--;

    int a, b, c;
    for(int i = 0;i < m;i++){
        cin >> a >> b >> c;
        a--;
        b--;
        graph[a].push_back(make_pair(b, c));
        graph[b].push_back(make_pair(a, c));
    }

    min_dist(0);
    min_dist(p);
    min_dist(q);


    if(dist[0][p] + dist[p][q] + dist[q][0] <= t){
        cout << t << endl;
        return 0;
    }

    int ans = -1;
    for(int i = 0;i < n;i++){
        for(int j = 0;j < n;j++){
            int ma = max(dist[q][i]+dist[q][j], dist[p][i]+dist[p][j]);
            if(dist[0][i]+dist[0][j] + ma <= t){
                ans = max(ans, t-ma);
            }
        }
    }

    cout << ans << endl;

    return 0;
}