#include<bits/stdc++.h>
#define rep(i,a,b) for(int i=a;i<b;i++)
#define rrep(i,a,b) for(int i=a;i>=b;i--)
#define fore(i,a) for(auto &i:a)
#define all(x) (x).begin(),(x).end()
//#pragma GCC optimize ("-O3")
using namespace std; void _main(); int main() { cin.tie(0); ios::sync_with_stdio(false); _main(); }
typedef long long ll; const int inf = INT_MAX / 2; const ll infl = 1LL << 60;
template<class T>bool chmax(T& a, const T& b) { if (a < b) { a = b; return 1; } return 0; }
template<class T>bool chmin(T& a, const T& b) { if (b < a) { a = b; return 1; } return 0; }
//---------------------------------------------------------------------------------------------------
template<typename T> using min_priority_queue = priority_queue<T, vector<T>, greater<T>>;
int vis[101010];
void dijk(int s, vector<vector<pair<int,int>>> &E, vector<ll> &D) {
	int N = E.size();
    rep(i, 0, N) D[i] = infl;
    rep(i, 0, N) vis[i] = 0;
 
    min_priority_queue<pair<ll, int>> que;
 
    D[s] = 0;
    que.push({ 0, s });
 
    while (!que.empty()) {
        auto q = que.top(); que.pop();
 
        ll cst = q.first;
        int cu = q.second;
 
        if (vis[cu]) continue;
        vis[cu] = 1;
 
        fore(p, E[cu]) {
            ll cst2 = cst + p.second;
            int to = p.first;
 
            if (chmin(D[to], cst2)) que.push({ D[to], to });
        }
    }
}
/*---------------------------------------------------------------------------------------------------
　　　　　　　　　　　 ∧＿∧
　　　　　 ∧＿∧ 　（´<_｀ ）　 Welcome to My Coding Space!
　　　　 （ ´_ゝ`）　/　 ⌒i     @hamayanhamayan
　　　　／　　　＼　 　  |　|
　　　 /　　 /￣￣￣￣/　　|
　 ＿_(__ﾆつ/　    ＿/ .| .|＿＿＿＿
　 　　　＼/＿＿＿＿/　（u　⊃
---------------------------------------------------------------------------------------------------*/














int N, M, P, Q, T;
//---------------------------------------------------------------------------------------------------
void _main() {
	cin >> N >> M >> P >> Q >> T;
	P--;
	Q--;

	vector<vector<pair<int, int>>> E(N);
	rep(i, 0, M) {
		int a, b, c; cin >> a >> b >> c;
		a--; b--;
		E[a].push_back({ b, c });
		E[b].push_back({ a, c });
	}

	vector<ll> s(N), p(N), q(N);

	dijk(0, E, s);
	dijk(P, E, p);
	dijk(Q, E, q);

	if (s[P] + p[Q] + q[0] <= T) {
		cout << T << endl;
		return;
	}

	ll ans = -1;
	rep(a, 0, N) rep(b, 0, N) {
		ll tot = s[a] + max(p[a] + p[b], q[a] + q[b]) + s[b];
		if (tot <= T) {
			chmax(ans, T - (tot - s[a] - s[b]));
		}
	}
	cout << ans << endl;
}