#include<iostream>
#include<string>
#include<algorithm>
#include<vector>
#include<iomanip>
#include<math.h>
#include<complex>
#include<queue>
#include<deque>
#include<stack>
#include<map>
#include<set>
#include<bitset>
#include<functional>
#include<assert.h>
#include<numeric>
using namespace std;
#define REP(i,m,n) for(int i=(int)(m) ; i < (int) (n) ; ++i )
#define rep(i,n) REP(i,0,n)
typedef long long ll;
typedef pair<int,int> pint;
typedef pair<ll,int> pli;
const int inf=1e9+7;
const ll longinf=1LL<<60 ;
const ll mod=1e9+7 ;

using G=vector<vector<pair<ll,int>>>;
vector<vector<ll>> bfs(G& v){
	int n=v.size();
	vector<vector<ll>> dist(n,vector<ll>(n,longinf));
	rep(i,n){
		dist[i][i]=0;
		priority_queue<pair<ll,int>> que;
		que.emplace(0,i);
		while(que.size()){
			ll d=-que.top().first;
			int cur=que.top().second;
			que.pop();
			if(d>dist[i][cur])continue;
			for(auto e : v[cur]){
				if(dist[i][e.second]>d+e.first){
					dist[i][e.second]=d+e.first;
					que.emplace(-dist[i][e.second],e.second);
				}
			}
		}
	}
	return dist;
}

int main(){
	int n,m,p,q,t;
	cin>>n>>m>>p>>q>>t;
	--p;--q;
	G v(n);
	rep(i,m){
		int a,b,c;
		cin>>a>>b>>c;
		--a;--b;
		v[a].emplace_back(c,b);
		v[b].emplace_back(c,a);
	}
	ll ans=-1;
	auto dist=bfs(v);
	ll ret=dist[0][p]+dist[p][q]+dist[q][0];
	if(ret<=t){
		cout<<t<<endl;
		return 0;
	}
	rep(i,n){
		ret=2*dist[0][i]+2*max(dist[i][p],dist[i][q]);
		if(ret<=t){
			ans=max(ans,t-ret+2*dist[0][i]);
		}
	}
	cout<<ans<<endl;
	return 0;
}