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

#define rep(i,j,n) for(int i=j;i<n;++i)
#define all(i) i.begin(),i.end()
#define rall(i) i.rbegin(), i.rend()
#define INF 1e9
#define LINF 1e18
const int mod = 1e9 + 7;

typedef long long i64;
typedef pair<int, int> pi;

template <class T> using vt = vector<T>;
template <class T> using vvt = vector<vector<T>>;

i64 gcd(i64 n, i64 m) {return (m == 0? n : gcd(m, n % m));}
i64 lcd(i64 n, i64 m) {return (n / gcd(n, m) * m);}
int dx[] = {1, 0, -1, 0};
int dy[] = {0, 1, 0, -1};

vt<i64> dijkstra(int s, vvt<pair<int, i64>> &edge, int n) {
  vt<i64> dist(n + 1, INF);
  dist[s] = 0;

  priority_queue<pair<int, i64>, vt<pair<int, i64>>, greater<pair<int, i64>>> que;
  que.push({s, 0});
  while(!que.empty()) {
    int v = que.top().first;
    i64 c = que.top().second;
    que.pop();

    if(c > dist[v]) continue;
    for(auto &nxt : edge[v]) {
      if(dist[v] + nxt.second < dist[nxt.first]) {
        dist[nxt.first] = dist[v] + nxt.second;
        que.push({nxt.first, dist[nxt.first]});
      }
    }
  }
  return dist;
}

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

  int n, m, p, q, t;
  cin >> n >> m >> p >> q >> t;
  vvt<pair<int, i64>> edge(n + 1);
  rep(i, 0, m) {
    int a, b, c;
    cin >> a >> b >> c;
    edge[a].push_back({b, c});
    edge[b].push_back({a, c});
  }

  auto dist = dijkstra(1, edge, n);
  auto distP = dijkstra(p, edge, n);
  auto distQ = dijkstra(q, edge, n);

  if(dist[p] + distP[q] + distQ[1] <= t) cout << t << endl;
  else if(max(2 * dist[p], 2 * dist[q]) > t) cout << -1 << endl;
  else {
    i64 ans = 0;
    rep(x, 1, n + 1) {
      rep(y, 1, n + 1) {
        if(dist[x] + max(distP[x] + distP[y], distQ[x] + distQ[y]) + dist[y] <= t) {
          ans = max(ans, t - max(distP[x] + distP[y], distQ[x] + distQ[y]));
        }
      }
    }
    cout << ans << endl;
  }
}