#include <bits/stdc++.h>
#define rep(i, n) for(int(i) = 0; (i) < (n); (i)++)
#define FOR(i, m, n) for(int(i) = (m); (i) < (n); (i)++)
#define ALL(v) (v).begin(), (v).end()
#define LLA(v) (v).rbegin(), (v).rend()
#define SZ(v) (v).size()
#define INT(...)                                                               \
    int __VA_ARGS__;                                                           \
    read(__VA_ARGS__)
#define LL(...)                                                                \
    ll __VA_ARGS__;                                                            \
    read(__VA_ARGS__)
#define DOUBLE(...)                                                            \
    double __VA_ARGS__;                                                        \
    read(__VA_ARGS__)
#define CHAR(...)                                                              \
    char __VA_ARGS__;                                                          \
    read(__VA_ARGS__)
#define STRING(...)                                                            \
    string __VA_ARGS__;                                                        \
    read(__VA_ARGS__)
#define VEC(type, name, size)                                                  \
    vector<type> name(size);                                                   \
    read(name)
using namespace std;
using ll = long long;
using pii = pair<int, int>;
using pll = pair<ll, ll>;
using Graph = vector<vector<int>>;
template <typename T> struct edge {
    int to;
    T cost;
    edge(int t, T c) : to(t), cost(c) {}
};
template <typename T> using WGraph = vector<vector<edge<T>>>;
const int INF = 1 << 30;
const ll LINF = 1LL << 60;
const int MOD = 1e9 + 7;
template <class T> inline vector<T> make_vec(size_t a, T val) {
    return vector<T>(a, val);
}
template <class... Ts> inline auto make_vec(size_t a, Ts... ts) {
    return vector<decltype(make_vec(ts...))>(a, make_vec(ts...));
}

void read() {}
template <class T> inline void read(T &a) { cin >> a; }
template <class T> inline void read(vector<T> &v) {
    for(auto &a : v)
        read(a);
}
template <class T, class S> inline void read(pair<T, S> &p) {
    read(p.first), read(p.second);
}
template <class Head, class... Tail>
inline void read(Head &head, Tail &... tail) {
    read(head), read(tail...);
}
template <class T> inline void chmax(T &a, T &b) { (a < b ? a = b : a); }
template <class T> inline void chmin(T &a, T &b) { (a > b ? a = b : a); }

template <typename T> void dijkstra(int s, vector<T> &d, WGraph<T> &G) {
    priority_queue<pair<T, int>, vector<pair<T, int>>, greater<pair<T, int>>>
        que;
    const auto INF = 1e15;
    fill(ALL(d), INF);
    d[s] = 0;
    que.push(make_pair(0, s));
    while(!que.empty()) {
        auto p = que.top();
        que.pop();
        int v = p.second;
        if(d[v] < p.first)
            continue;
        for(auto e : G[v]) {
            if(d[e.to] > d[v] + e.cost) {
                d[e.to] = d[v] + e.cost;
                que.push(make_pair(d[e.to], e.to));
            }
        }
    }
}

int main() {
    ios::sync_with_stdio(false);
    cin.tie(nullptr);
    INT(n, m, p, q, t);
    p--, q--;
    WGraph<ll> g(n);
    rep(i, m) {
        INT(a, b, c);
        a--, b--;
        g[a].push_back(edge<ll>(b, c));
        g[b].push_back(edge<ll>(a, c));
    }
    vector<ll> dist0(n), distp(n), distq(n);
    dijkstra(0, dist0, g);
    dijkstra(p, distp, g);
    dijkstra(q, distq, g);

    if(min(dist0[p] + distp[q] + distq[0], dist0[q] + distq[p] + distp[0]) <=
       t) {
        cout << t << endl;
        return 0;
    }
    ll res = -1;
    for(int i = 0; i < n; i++) {
        for(int j = 0; j < n; j++) {
            if(dist0[i] + max(distp[i] + distp[j], distq[i] + distq[j]) +
                   dist0[j] <=
               t) {
                res =
                    max(res, t - max(distp[i] + distp[j], distq[i] + distq[j]));
            }
        }
    }
    cout << res << endl;
}