#include <bits/stdc++.h>
#define Int int64_t

using namespace std;
using P = pair<Int, Int>;

struct edge { int to; Int cost; };
void dijkstra(vector<vector<edge>>& G, vector<Int>& d, int s) {
	priority_queue<P, vector<P>, greater<P>> que;
	d[s] = 0;
	que.push(P(0, s));

	while (!que.empty()) {
		P p = que.top();
		que.pop();
		int v = p.second;
		if (d[v] < p.first) { continue; }

		for (int i = 0; i < G[v].size(); ++i) {
			edge e = G[v][i];
			if (d[e.to] > d[v] + e.cost) {
				d[e.to] = d[v] + e.cost;
				que.push(P(d[e.to], e.to));
			}
		}
	}
}

int main() {
	const Int INF = 1e18;
	Int N, M, P, Q, T;
	cin >> N >> M >> P >> Q >> T;
	--P; --Q;
	vector<vector<edge>> G(N);
	for (int i = 0; i < M; ++i) {
		int a, b, c;
		cin >> a >> b >> c;
		--a; --b;
		G[a].push_back({b, c});
		G[b].push_back({a, c});
	}

	vector<Int> d0(N, INF), dP(N, INF), dQ(N, INF);
	dijkstra(G, d0, 0);
	dijkstra(G, dP, P);
	dijkstra(G, dQ, Q);
	if (d0[P] + dP[Q] + dQ[0] <= T) {
		cout << T << endl;
		return 0;
	}
	Int res = -1;
	for (int i = 0; i < N; ++i) {
		for (int j = 0; j < N; ++j) {
			Int x = d0[i] + d0[j];
			Int y = max(dP[i] + dP[j], dQ[i] + dQ[j]);
			if (x + y <= T) {
				res = max(res, T - y);
			}
		}
	}
	cout << res << endl;

	return 0;
}