#include<bits/stdc++.h> #define exoworldgd cin.tie(0)->sync_with_stdio(0),cout.tie(0) #define int long long #define P array<int,2> using namespace std; const int INF=1e18; int n,m,s,t,l,k,ans,d1[200005],d2[200005]; vector<P>g[200005]; void f(int st,int*d){ priority_queue<P,vector<P>,greater<>>pq; for(int i=0;i<n;i++)d[i]=1e18; d[st]=0,pq.push({0,st}); while(pq.size()){ auto[di,u]=pq.top();pq.pop(); if(di<=d[u])for(auto[v,w]:g[u])if(d[u]+w<d[v])d[v]=d[u]+w,pq.push({d[v],v}); } } signed main(void){ exoworldgd; cin>>n>>m>>s>>t>>l>>k,s--,t--; for(int i=0,a,b,c;i<m;i++)cin>>a>>b>>c,a--,b--,g[a].push_back({b,c}),g[b].push_back({a,c}); f(s,d1),f(t,d2); if(d1[t]<=k){cout<<n*(n-1)/2;return 0;} sort(d1,d1+n),sort(d2,d2+n); for(int i=0,j=n-1;i<n;i++){ while(j+1&&d1[i]+d2[j]+l>k)j--; ans+=j+1; } cout<<ans; }