#include <cstdio>
#include <queue>
using namespace std;
typedef long long ll;
const int N = 2505;
const int M = 10005;
struct Edge {
	int v, next;
} edge[2 * M];
int head[N];
int cnt;
void add_edge(int u, int v) {
	cnt++;
	edge[cnt].v = v;
	edge[cnt].next = head[u];
	head[u] = cnt;
}
ll val[N];
int dis[N][N];
bool vis[N];
void bfs(int s) {
	for (int i = 0; i < N; i++) {
		vis[i] = false;
	}
	queue < int > q;
	q.push(s);
	dis[s][s] = -1;
	vis[s] = true;
	while (!q.empty()) {
		int u = q.front();
		q.pop();
		for (int v, i = head[u]; i != 0; i = edge[i].next) {
			v = edge[i].v;
			if (!vis[v]) {
				dis[s][v] = dis[s][u] + 1;
				q.push(v);
				vis[v] = true;
			}
		}
	}
}
int best[N][3];
int main() {
	int n, m, k;
	scanf("%d %d %d", &n, &m, &k);
	val[1] = -4000000000000000000;
	for (int i = 2; i <= n; i++) {
		scanf("%lld", &val[i]);
	}
	for (int u, v, i = 1; i <= m; i++) {
		scanf("%d %d", &u, &v);
		add_edge(u, v);
		add_edge(v, u);
	}
	for (int i = 1; i <= n; i++) {
		bfs(i);
	}
	for (int i = 2; i <= n; i++) {
		best[i][0] = best[i][1] = best[i][2] = 1;
		for (int j = 2; j <= n; j++) {
			if (i != j && dis[1][j] <= k && dis[j][i] <= k) {
				if (val[j] > val[best[i][0]]) {
					best[i][2] = best[i][1];
					best[i][1] = best[i][0];
					best[i][0] = j;
				} else if (val[j] > val[best[i][1]]) {
					best[i][2] = best[i][1];
					best[i][1] = j;
				} else if (val[j] > val[best[i][2]]) {
					best[i][2] = j;
				}
			}
		}
	}
	ll ans = 0;
	int a, b, c, d;
	for (b = 2; b <= n; b++) {
		for (c = 2; c <= n; c++) {
			for (int i = 0; i < 3; i++) {
				for (int j = 0; j < 3; j++) {
					a = best[b][i];
					d = best[c][j];
					if (a != 1 && a != c && a != d && b != c && d != 1 && d != b && dis[b][c] <= k) {
						ans = max(ans, val[a] + val[b] + val[c] + val[d]);
					}
				}
			}
		}
	}
	printf("%lld", ans);
	return 0;
}