#include<iostream>
#include<string>
#include<iomanip>
#include<cmath>
#include<vector>
#include<algorithm>
#include<queue>
#include<cassert>

using namespace std;

#define int long long
#define rep(i,n) for(int i = 0; i < (n); i++)
#define endl "\n"

const long long INF = (long long)1e16;
const long long MOD = (long long)1e9 + 7; 

string yn(bool f){return f?"Yes":"No";}
string YN(bool f){return f?"YES":"NO";}
	
int N, M, P, Q, T;

void  dijkstra(vector<int> &dis, vector<vector<pair<int,int>>> G, int s){
	priority_queue<pair<int,int>, vector<pair<int,int>>, greater<pair<int,int>>> Q;
	
	dis.resize(N, INF);
	
	dis[s] = 0;
	
	Q.push(make_pair(0,s));
	
	while(!Q.empty()){
		pair<int,int> p = Q.top(); Q.pop();
		int n = p.second;
		if(dis[n] < p.first) continue;
		
		for(pair<int,int> y : G[n]){
			if(dis[n] + y.second < dis[y.first]){
				dis[y.first] = dis[n] + y.second;
				Q.push(make_pair(dis[y.first], y.first));
			}
		}
		
	}
}

signed main(){
	cin.tie(0);
	ios::sync_with_stdio(false);
	cout<<fixed<<setprecision(10);
	
	vector<vector<pair<int,int>>> G;
	vector<int> dis, disp, disq;

	int ans = -1;
	int a, b, c;
	
	cin>>N>>M>>P>>Q>>T;
	
	P--, Q--;
	
	G.resize(N);
	
	for(int i = 0; i < M; i++){
		cin>>a>>b>>c;
		a--,b--;
		assert(a < N);
		assert(b < N);
		G[a].push_back(make_pair(b,c));
		G[b].push_back(make_pair(a,c));
	}
	
	dijkstra(dis, G, 0);
	dijkstra(disp, G, P);
	dijkstra(disq, G, Q);
	
	if(dis[P] + disp[Q] + disq[0] <= T) ans = T;
	if(dis[Q] + disq[P] + disp[0] <= T) ans = T;

	for(int i = 0; i < N; i++){
		for(int j = 0; j < N; j++){
			if(dis[i] + max(disp[i] + disp[j], disq[i] + disq[j]) + dis[j] > T) continue;
			ans = max(ans, T - max(disp[i] + disp[j], disq[i] + disq[j]));
		}
	}
	
	cout<<ans<<endl;
	
	return 0;
}