#include <cstdio>

#include <algorithm>

#include <ext/pb_ds/priority_queue.hpp>

#define maxn 10010

#define maxm 50010

using namespace std;

const long long inf = 0x3f3f3f3f3f3f3f3f;

int n, m, S, T, s, ans = -1;

int f[maxn], rnk[maxn];

inline bool cmp(int a, int b) {return f[a] < f[b];}

int head[maxn], cnt;

struct Edge {

	int to, nxt, w;

} e[maxm << 1];

void add(int a, int b, int c) {

	e[++cnt] = (Edge) {b, head[a], c}; head[a] = cnt;

}

long long d[maxn];

struct cmpq {

	inline bool operator () (const int &a, const int &b) const {

		return d[a] > d[b];

	}

};

__gnu_pbds::priority_queue<int, cmpq> q;

__gnu_pbds::priority_queue<int, cmpq>::point_iterator iter[maxn];

bool check(int mid) {

	if (f[S] > mid) return false;

	while (!q.empty()) q.pop();

	for (int i = 1; i <= n; i++) d[i] = inf, iter[i] = q.push(i);

	d[S] = 0;

	q.modify(iter[S], S);

	while (!q.empty()) {

		int u = q.top(); q.pop();

		for (int i = head[u]; i; i = e[i].nxt) {

			int v = e[i].to;

			if (f[v] > mid) continue;

			if (d[v] > d[u] + e[i].w) {

				d[v] = d[u] + e[i].w;

				if (d[T] <= s) return true;

				q.modify(iter[v], v);

			}

		}

	}

	return d[T] <= s;

}

int main() {

	scanf("%d%d%d%d%d", &n, &m, &S, &T, &s);

	for (int i = 1; i <= n; i++) scanf("%d", &f[i]), rnk[i] = i;

	for (int i = 1; i <= m; i++) {

		int a, b, c;

		scanf("%d%d%d", &a, &b, &c);

		if (a == b) continue;

		add(a, b, c);

		add(b, a, c);

	}

	sort(rnk + 1, rnk + n + 1, cmp);

	int L = 1, R = n;

	while (L <= R) {

		int mid = L + R >> 1;

		if (check(f[rnk[mid]])) {

			ans = mid;

			R = mid - 1;

		} else L = mid + 1;

	}

	if (~ans) printf("%d\n", f[rnk[ans]]);

	else puts("-1");

	return 0;

}