#include <bits/stdc++.h>
#define ll long long
using namespace std;
ll n;
vector<vector<pair<ll,ll>>> adj;
vector<ll> dijkstra(ll s) {
vector<ll> dist(n, 1e18);
dist[s] = 0;
priority_queue<pair<ll,ll>, vector<pair<ll,ll>>, greater<pair<ll,ll>>> pq;
pq.push({0, s});
while(!pq.empty()) {
auto [d,u] = pq.top();
pq.pop();
if (d>dist[u]) continue;
for (auto [v,w] : adj[u]) {
if (dist[v]>dist[u]+w) {
dist[v] = dist[u]+w;
pq.push({dist[v],v});
}
}
}
return dist;
}
int main() {
ios_base::sync_with_stdio(0);
cin.tie(0);
ll m,s,t,l,k;
cin >> n >> m >> s >> t >> l >> k;
s--; t--;
adj.resize(n);
for (int i=0; i<m; i++) {
ll a,b,c;
cin >> a >> b >> c;
a--; b--;
adj[a].push_back({b,c});
adj[b].push_back({a,c});
}
vector<ll> dists = dijkstra(s);
vector<ll> distt = dijkstra(t);
ll res = 0;
for (int i=0; i<n; i++) {
for (int j=i+1; j<n; j++) {
if (dists[i]+distt[j]<=k-l) {
res++;
}
if (dists[j]+distt[i]<=k-l) {
res++;
}
}
}
cout << res;
}
