#include<bits/stdc++.h>
using namespace std;
#define inf INT_MAX
#define INF LLONG_MAX
#define ll long long
#define ull unsigned long long
#define M (int)(1e9+7)
#define P pair<int,int>
#define FOR(i,m,n) for(int i=(int)m;i<(int)n;i++)
#define RFOR(i,m,n) for(int i=(int)m;i>=(int)n;i--)
#define rep(i,n) FOR(i,0,n)
#define rrep(i,n) RFOR(i,n,0)
#define all(a) a.begin(),a.end()
const int vx[4] = {0,1,0,-1};
const int vy[4] = {1,0,-1,0};
#define F first
#define S second
#define PB push_back
#define EB emplace_back
#define int ll
#define vi vector<int>
#define IP pair<int,P>
#define PI pair<P,int>
#define PP pair<P,P>
#define Yes(f){cout<<(f?"Yes":"No")<<endl;}
#define YES(f){cout<<(f?"YES":"NO")<<endl;}
int Madd(int x,int y) {return (x+y)%M;}
int Msub(int x,int y) {return (x-y+M)%M;}
int Mmul(int x,int y) {return (x*y)%M;}



template< typename T >
struct edge {
  int src, to;
  T cost;

  edge(int to, T cost) : src(-1), to(to), cost(cost) {}

  edge(int src, int to, T cost) : src(src), to(to), cost(cost) {}

  edge &operator=(const int &x) {
    to = x;
    return *this;
  }

  operator int() const { return to; }
};

template< typename T >
using Edges = vector< edge< T > >;
template< typename T >
using WG = vector< Edges< T > >;
using UG = vector< vector< int > >;
template< typename T >
using Matrix = vector< vector< T > >;



template< typename T >
vector<T> dijkstra(WG<T> &g,int s){
  const auto lim = numeric_limits<T>::max();
  vector<T> dist(g.size(),lim);
  using Pi = pair<T,int>;
  priority_queue<Pi,vector<Pi>,greater<Pi>> q;
  dist[s] = 0;
  q.emplace(dist[s],s);
  while(!q.empty()){
    T cost;
    int idx;
    tie(cost,idx) = q.top();
    q.pop();
    if(dist[idx] < cost) continue;
    for( auto &e : g[idx]){
      auto next_cost = cost + e.cost;
      if(dist[e.to] <= next_cost) continue;
      dist[e.to] = next_cost;
      q.emplace(dist[e.to],e.to);
    }
  }
  return dist;
}


signed main(){
  cin.tie(0);
  ios::sync_with_stdio(false);
  cout<<fixed<<setprecision(20);

  int n,m,p,q,t;
  cin>>n>>m>>p>>q>>t;
  p--;q--;
  WG<int> es(n);
  rep(i,m){
    int a,b,c;
    cin>>a>>b>>c;
    a--;b--;
    es[a].PB(edge<int>(b,c));
    es[b].PB(edge<int>(a,c));
  }

  vi dists=dijkstra(es,0);
  vi distp=dijkstra(es,p);
  vi distq=dijkstra(es,q);


  if(dists[p]+dists[q]+distp[q]<=t){
    cout<<t<<endl;
  }else if(max(2*dists[p],2*dists[q])>t){
    cout<<-1<<endl;
  }else{
    int ans=-1;
    rep(x,n){
      rep(y,n){
        if(dists[x]+max(distp[x]+distp[y],distq[x]+distq[y])+dists[y]>t) continue;
        ans=max(ans,t-max(distp[x]+distp[y],distq[x]+distq[y]));
      }
    }
    cout<<ans<<endl;
  }
}