#include <bits/stdc++.h>
#include <ext/pb_ds/assoc_container.hpp>
#include <ext/pb_ds/tree_policy.hpp>
using namespace __gnu_pbds;
//#define ordered_set tree<int, null_type,less<int>, rb_tree_tag,tree_order_statistics_node_update>
#define orderedset tree<long long, null_type, less_equal<long long>, rb_tree_tag, tree_order_statistics_node_update>
using namespace std;
#define ll long long
#define pb push_back
#define fr first
#define sc second
#define int ll
#define all(x) x.begin(),x.end()
const int N=2e5+5;
vector<pair<int,int>> g[N];
vector<int> dist1,dist2;
void djks(int x, int c) {
vector<int> dist(N,1e18);
priority_queue<pair<int,int>,vector<pair<int,int>>,greater<pair<int,int>>> pq;
pq.push({0,x});
dist[x]=0;
while(!pq.empty()) {
int k=pq.top().sc;
int d=pq.top().fr;
pq.pop();
if(dist[k]!=d) continue;
for(auto it: g[k]) {
if(dist[it.fr]>d+it.sc) {
dist[it.fr]=d+it.sc;
pq.push({dist[it.fr],it.fr});
}
}
}
if(c==0) dist1=dist;
else dist2=dist;
}
void solve(){
int n,m;cin>>n>>m;
int s,t,l,k;cin>>s>>t>>l>>k;
for(int i=0;i<m;i++) {
int a,b,c;cin>>a>>b>>c;
g[a].pb({b,c});
g[b].pb({a,c});
}
djks(s,0);
djks(t,1);
if(dist1[t]<=k) {
cout<<n*(n-1)/2;
return;
}
int ans=0;
orderedset a,b;
a.insert(1e18);
b.insert(1e18);
for(int i=1;i<=n;i++){
int A=a.order_of_key(k-(dist1[i]+l)+1);
int B=b.order_of_key(k-(dist2[i]+l)+1);
//cout<<A<<' '<<B<<endl;
ans+=A;
ans+=B;
a.insert(dist2[i]);
b.insert(dist1[i]);
}
cout<<ans<<endl;
}
signed main(){
int t=1;//cin>>t;
while(t--){
solve();
}
}
//#endif
