#include <bits/stdc++.h> using namespace std; #define int long long #define pi pair<int,int> const int INF = 4e18; int32_t main() { cin.tie(0)->sync_with_stdio(0); int n,m; cin>> n>> m; int s,t,l,k; cin>> s>> t>> l>> k; vector<vector<pair<int,int>>> g(n+1); for (int i=0; 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> dist(n+1, INF), rdist(n+1, INF); dist[s] = 0; rdist[t] = 0; priority_queue<pi, vector<pi>, greater<pi>> pq; pq.push({0, s}); while (!pq.empty()) { int u=pq.top().second, d=pq.top().first; pq.pop(); if (dist[u] < d) continue; for (auto &x : g[u]) { int v=x.first, w=x.second; if (dist[v] > dist[u]+w) { dist[v] = dist[u]+w; pq.push({dist[v], v}); } } } pq.push({0, t}); while (!pq.empty()) { int u=pq.top().second, d=pq.top().first; pq.pop(); if (rdist[u] < d) continue; for (auto &x : g[u]) { int v=x.first, w=x.second; if (rdist[v] > rdist[u]+w) { rdist[v] = rdist[u]+w; pq.push({rdist[v], v}); } } } int ans = 0; for (int i=1; i<=n; i++) { for (int j=i+1; j<=n; j++) { if (dist[i] + l + rdist[j] <= k) ans++; else if (rdist[i] + l + dist[j] <= k) ans++; } } cout<< ans; }