#include <bits/stdc++.h>
using namespace std;
typedef long long   signed int LL;
typedef long long unsigned int LU;
#define incID(i, l, r) for(LL i = (l)    ; i <  (r); ++i)
#define incII(i, l, r) for(LL i = (l)    ; i <= (r); ++i)
#define decID(i, l, r) for(LL i = (r) - 1; i >= (l); --i)
#define decII(i, l, r) for(LL i = (r)    ; i >= (l); --i)
#define inc(i, n)  incID(i, 0, n)
#define inc1(i, n) incII(i, 1, n)
#define dec(i, n)  decID(i, 0, n)
#define dec1(i, n) decII(i, 1, n)
#define inID(v, l, r) ((l) <= (v) && (v) <  (r))
#define inII(v, l, r) ((l) <= (v) && (v) <= (r))
#define PB push_back
#define EB emplace_back
#define MP make_pair
#define FI first
#define SE second
#define  ALL(v)  v.begin(),  v.end()
#define RALL(v) v.rbegin(), v.rend()
template<typename T> bool setmin  (T & a, T b) { if(b <  a) { a = b; return true; } else { return false; } }
template<typename T> bool setmax  (T & a, T b) { if(b >  a) { a = b; return true; } else { return false; } }
template<typename T> bool setmineq(T & a, T b) { if(b <= a) { a = b; return true; } else { return false; } }
template<typename T> bool setmaxeq(T & a, T b) { if(b >= a) { a = b; return true; } else { return false; } }
LL mo(LL a, LL b) { assert(b > 0); a %= b; if(a < 0) { a += b; } return a; }
LL fl(LL a, LL b) { assert(b > 0); return (a > 0 ? a / b : (a - b + 1) / b); }
LL ce(LL a, LL b) { assert(b > 0); return (a < 0 ? a / b : (a + b - 1) / b); }
template<typename T> T gcd(T a, T b) { return (b == 0 ? a : gcd(b, a % b)); }
template<typename T> T lcm(T a, T b) { return a / gcd(a, b) * b; }
#define bit(b, i) (((b) >> (i)) & 1)
#define BC __builtin_popcountll
#define SC static_cast
#define SI(v) SC<int>(v.size())
#define SL(v) SC<LL >(v.size())
#define RF(e, v) for(auto & e: v)
#define ef else if
#define UR assert(false)

// ---- ----

template<typename T> class RPQ : public priority_queue<T, vector<T>, greater<T>> { };
template<typename C> void dijkstra(int s, vector<pair<int, C>> g[], C d[]) {
	RPQ<pair<C, int>> q;
	d[s] = 0;
	q.emplace(d[s], s);
	while(! q.empty()) {
		C   c = q.top().FI;
		int v = q.top().SE;
		q.pop();
		if(d[v] != c) { continue; }
		for(auto & e : g[v]) {
			int ev = e.FI;
			C   ec = e.SE;
			if(setmin(d[ev], d[v] + ec)) { q.emplace(d[ev], ev); }
		}
	}
}

const int M = 2000;
LL n, m, p, q, t, d0[M], dp[M], dq[M], INF = 1e15;
vector<pair<int, LL>> g[M];

int main() {
	cin >> n >> m >> p >> q >> t;
	p--; q--;
	inc(i, m) {
		LL a, b, c;
		cin >> a >> b >> c;
		a--; b--;
		g[a].EB(b, c);
		g[b].EB(a, c);
	}
	
	inc(i, n) { d0[i] = dp[i] = dq[i] = INF; }
	dijkstra(0, g, d0);
	dijkstra(p, g, dp);
	dijkstra(q, g, dq);
	
	if(d0[p] + dp[q] + dq[0] <= t) { cout << t << endl; }
	else {
		LL ans = -1;
		inc(i, n) {
		inc(j, n) {
			LL ij = max(dp[i] + dp[j], dq[i] + dq[j]);
			if(d0[i] + ij + d0[j] > t) { continue; }
			setmax(ans, t - ij);
		}
		}
		cout << ans << endl;
	}
	
	return 0;
}