#include using namespace std; //#include //using multiInt = boost::multiprecision::cpp_int; using ll = long long int; using ld = long double; using pii = pair; using pll = pair; template using smaller_queue = priority_queue, greater>; const int MOD_TYPE = 1; const ll MOD = (MOD_TYPE == 1 ? (ll)(1e9 + 7) : 998244353); const int INF = (int)1e9; const ll LINF = (ll)4e18; const ld DINF = 1e12; const ld PI = acos(-1.0); const ld EPS = 1e-11; #define REP(i, m, n) for (ll i = m; i < (ll)(n); ++i) #define rep(i, n) REP(i, 0, n) #define MP make_pair #define MT make_tuple #define YES(n) cout << ((n) ? "YES" : "NO") << "\n" #define Yes(n) cout << ((n) ? "Yes" : "No") << endl #define Possible(n) cout << ((n) ? "Possible" : "Impossible") << endl #define possible(n) cout << ((n) ? "possible" : "impossible") << endl #define Yay(n) cout << ((n) ? "Yay!" : ":(") << endl #define all(v) v.begin(), v.end() #define NP(v) next_permutation(all(v)) #define dbg(x) cerr << #x << ":" << x << endl; vector Dx = {0, 0, -1, 1, -1, 1, -1, 1, 0}; vector Dy = {1, -1, 0, 0, -1, -1, 1, 1, 0}; template struct dijkstra { static const int MAX_V = 200010; const T INF_d; dijkstra(T INF_d_ = LINF) : INF_d(INF_d_) {} struct edge { int to; T cost; }; vector E[MAX_V]; T d[MAX_V]; using pt = pair; void add_edge(int a, int b, T c, bool undirected = false) { E[a].push_back(edge{b, c}); if (undirected) E[b].push_back(edge{a, c}); } void calc(int s) { priority_queue, greater> que; fill(d, d + MAX_V, INF_d); que.emplace(0LL, s); d[s] = 0; while (!que.empty()) { pt p = que.top(); que.pop(); int v = p.second; if (d[v] < p.first) continue; for (auto &&e : E[v]) { if (d[e.to] > d[v] + e.cost) { d[e.to] = d[v] + e.cost; que.emplace(d[e.to], e.to); } } } } }; int main() { cin.tie(0); ios::sync_with_stdio(false); cout << setprecision(30) << setiosflags(ios::fixed); ll n, m, p, q, t; cin >> n >> m >> p >> q >> t; p--, q--; dijkstra<> ds, ds_i; rep(i, m) { ll a, b, c; cin >> a >> b >> c; a--, b--; ds.add_edge(a, b, c, true); ds_i.add_edge(a, b, c, true); } ds.calc(0); ll Max = -1; ll d = ds.d[p] + ds.d[q]; rep(i, n) { ll t0 = ds.d[i]; ds_i.calc(i); if (i == p) d += ds_i.d[q]; ll t1 = ds_i.d[p], t2 = ds_i.d[q]; ll total = 2 * t0 + 2 * max(t1, t2); if (total > t) continue; ll together = t - 2 * max(t1, t2); Max = max(Max, together); } if (d <= t) Max = t; cout << Max << endl; return 0; }