#include <bits/stdc++.h>

using namespace std;

#define REP(i,n) for(int i=0; i<(int)(n); i++)
const long long INF = 1LL<<50;

vector<long long> dijkstra(const vector<vector<pair<int, int> > > &edges, int s) {
  int n = edges.size();
  vector<long long> dist(n, INF);
  priority_queue<pair<long long, int>, vector<pair<long long, int>>, greater<pair<long long, int>> > Q;

  Q.emplace(0, s);
  dist[s] = 0;
  
  while (!Q.empty()) {
    long long d;
    int v;
    
    tie(d, v) = Q.top();
    Q.pop();

    if (d > dist[v]) continue;
    dist[v] = d;
    for (auto &[w, cost] : edges[v]) {
      if (d + cost < dist[w]) {
        dist[w] = d + cost;
        Q.emplace(dist[w], w);
      }
    }
  }

  return dist;
}


int main() {
  ios_base::sync_with_stdio(0);
  cin.tie(0);

  int n, m, p, q, t;
  cin >> n >> m >> p >> q >> t;
  --p, --q;

  vector<vector<pair<int, int> > > edges(n);
  for (int i = 0; i < m; i++) {
    int a, b, c;
    cin >> a >> b >> c;
    --a, --b;
    edges[a].emplace_back(b, c);
    edges[b].emplace_back(a, c);
  }

  vector<long long> dp = dijkstra(edges, p);
  vector<long long> dq = dijkstra(edges, q);
  vector<long long> ds = dijkstra(edges, 0);

  long long ret = -1;
  for (int i = 0; i < n; i++) {
    long long tmp;
    // ずっと一緒
    tmp = 2 * ds[i] + dp[i] + dq[i] + dp[q];
    if (t >= tmp)
      ret = t;
    
    // 途中で別れる
    tmp = 2 * ds[i] + 2 * max(dp[i], dq[i]);
    if (t >= tmp) {
      ret = max(ret, t - tmp + 2 * ds[i]);
    }
  }

  cout << ret << endl;
  
  return 0;
}