#include <bits/stdc++.h> using namespace std; #define int long long const int maxn = 2e5 + 5; vector<pair<int, int>> g[maxn]; vector<int> dijkstra(int source, int n){ vector<int> dist(n + 1, 1e18); dist[source] = 0; priority_queue<array<int, 2>, vector<array<int, 2>>, greater<array<int, 2>>> pq; pq.push({0, source}); while(pq.size()){ auto [d, u] = pq.top(); pq.pop(); if(d > dist[u]) continue; for(auto [v, w]: g[u]){ if(dist[v] > d + w){ dist[v] = d + w; pq.push({dist[v], v}); } } } return dist; } signed main(){ ios_base::sync_with_stdio(false); cin.tie(0); cout.tie(0); int n, m, s, t, l, k; cin >> n >> m >> s >> t >> l >> k; for(int i = 1; i <= m; i++){ int u, v, w; cin >> u >> v >> w; g[u].push_back({v, w}); g[v].push_back({u, w}); } vector<int> dists = dijkstra(s, n); vector<int> distt = dijkstra(t, n); if(dists[t] <= k) cout << n * (n - 1) / 2; else{ sort(dists.begin() + 1, dists.end()); int ans = 0; for(int i = 1; i <= n; i++){ int c = k - (distt[i] + l); ans += upper_bound(dists.begin() + 1, dists.end(), c) - dists.begin() - 1; } cout << ans; } }