rt,https://www.luogu.com.cn/record/176921560，样例三也挂了

# include <bits/stdc++.h>

# define I return

# define AK 0

# define IOI ;

using namespace std;

typedef long long ll;

typedef pair <int, int> pii;

typedef pair <ll, int> pli;

int n, m, k, x, y, dis[2505][2505];

ll a[2505], maxx;

bitset <2505> vis[2505];

vector <int> v[2505], ma[2505];

priority_queue <pli> pq;

queue <int> q;

void bfs (const int s) {

	memset (dis[s], -1, sizeof dis[s]);

	q.emplace (s), dis[s][s] = 0;

	while (! q.empty ()) {

		x = q.front ();

		q.pop ();

		if (x ^ s) {

			vis[s][x] = 1;

			if (s ^ 1 && vis[1][x]) {

				pq.push ({a[x], x});

				if (pq.size () > 5)
					pq.pop ();

			}

		}

		if (dis[s][x] > k)
			continue ;

		for (const int& i : v[x])
			if (! ~ dis[s][i])
				q.emplace (i), dis[s][i] = dis[s][x] + 1;

	}

	while (! pq.empty ())
		ma[s].emplace_back (pq.top ().second), pq.pop ();

	return ;

}

int main () {

	ios::sync_with_stdio (0);

	cin.tie (0);

	cout.tie (0);

	cin >> n >> m >> k;
//	cerr << n << '\n';
	for (int i = 2; i <= n; ++ i)
		cin >> a[i];
//	cerr << "----------";
	while (m --)
		cin >> x >> y, v[x].emplace_back (y), v[y].emplace_back (x);

	for (int i = 1; i <= n; ++ i)
		bfs (i);
//	cerr << vis[3][5] << '\n';
//	for (int i = 1; i <= n; ++ i) {
//		cerr << i << ':';
//		for (const int& j : v[i]) cerr << j << ' ';
//		cerr << '\n';
//	}
	for (int i = 2; i <= n; ++ i)
		for (int j = 2; j <= n; ++ j)
			if (vis[i][j])
				for (const int& x : ma[i])
					if (x != i && x != j)
						for (const int& y : ma[j])
							if (x != y && y != i && y != j) //cerr << "1->" << x << "->" << i << "->" << j << "->" << y << "->1:" << a[x] + a[i] + a[j] + a[y] << '\n',
								maxx = max (maxx, a[x] + a[i] + a[j] + a[y]);

	cout << maxx;

	return 0;

}