#include <bits/stdc++.h>
using namespace std;
using ll = long long;
using pii = pair<ll, ll>;
const int nx = 2e5+5;
const ll INF = 1e18;
ll n, m, s, t, l, k, res;
vector<ll> distS(nx, INF), distT(nx, INF);
vector<pii> adj[nx];
priority_queue<pii, vector<pii>, greater<pii>> pq;
void dijkstra(ll src, vector<ll>& dist)
{
dist[src] = 0;
pq.push({0, src});
while(!pq.empty())
{
auto [cw, u] = pq.top();
pq.pop();
for(auto [v, nw] : adj[u])
{
if(dist[v] > dist[u] + nw)
{
dist[v] = dist[u] + nw;
pq.push({dist[v], v});
}
}
}
}
int main()
{
cin.tie(NULL)->sync_with_stdio(false);
cin >> n >> m;
cin >> s >> t >> l >> k;
for(int i=0;i<m;i++)
{
ll u, v, w;
cin >> u >> v >> w;
adj[u].push_back({v, w});
adj[v].push_back({u, w});
}
dijkstra(s, distS);
dijkstra(t, distT);
for(int i=1;i<=n;i++)
{
for(int j=1;j<=n;j++)
{
if(distS[i] == INF || distT[j] == INF) continue;
ll d = distS[i] + l + distT[j];
if(d <= k) {
// cout << i << ' ' << j << '\n';
res++;
}
}
}
cout << res ;
return 0;
}
