#include <cstdio>
#include <cstdlib>
#include <cmath>
#include <climits>
#include <cassert>
#include <cstdint>
#include <iostream>
#include <iomanip>
#include <string>
#include <stack>
#include <queue>
#include <vector>
#include <map>
#include <set>
#include <algorithm>
#include <numeric>
#include <bitset>

using namespace std;

using ll =  long long;
using Pll = pair<ll, ll>;
using Pii = pair<int, int>;

constexpr int MAX_N = 2000;

vector< vector<Pll> > edges(MAX_N);

class Dijkstra {
    public: 
    ll d[MAX_N];
    ll start = -1;

    Dijkstra(ll start): start(start) {
        fill(d, d+MAX_N, 1LL<<30);
        d[start] = 0;

        priority_queue< Pll, vector<Pll>, greater<Pll> > que;
        que.push(Pll(0, start));

        while(!que.empty()){
            Pll v = que.top(); que.pop();
            if(d[v.second] < v.first) continue;
            for(Pll e: edges[v.second]){
                if(d[e.first] > d[v.second] + e.second){
                    d[e.first] = d[v.second] + e.second;
                    que.push(Pll(d[e.first], e.first));
                }
            }
        }
    }

    ll get(ll x) {
        return d[x];
    }
};

int main() {
    int n,m,p,q; ll t;
    cin >> n >> m >> p >> q >> t;
    --p; --q;
    int a,b; ll c;
    for(int i=0;i<m;++i){
        cin >> a >> b >> c;
        --a; --b;
        edges[a].emplace_back(b, c);
        edges[b].emplace_back(a, c);
    }

    Dijkstra d_0 = Dijkstra(0), d_p = Dijkstra(p), d_q = Dijkstra(q);
    assert(d_0.get(p) == d_p.get(0));
    assert(d_p.get(q) == d_q.get(p));
    assert(d_q.get(0) == d_0.get(q));

    ll ans = -1LL;
    if(d_0.get(p) + d_p.get(q) + d_q.get(0) <= t) {
        ans = t;
    } else {
        for(int r1=0;r1<n;++r1) {
            ll tt = 2LL * (d_0.get(r1) + max(d_p.get(r1), d_q.get(r1)));
            if(tt <= t) {
                ans = max(t-2LL*max(d_p.get(r1), d_q.get(r1)), ans);
            }

            for(int r2=0;r2<n;++r2) {
                if(r1 == r2) continue;
                tt = d_0.get(r1) + max(d_p.get(r1)+d_p.get(r2), d_q.get(r1)+d_q.get(r2)) + d_0.get(r2);
                if(tt <= t) {
                    ans = max(t - max(d_p.get(r1)+d_p.get(r2), d_q.get(r1)+d_q.get(r2)), ans);
                }
            }
        }
    }

    cout << ans << endl;
}