#include<iostream>
#include<cstdio>
#include<cstring>
#include<queue>
#include<algorithm>
#include<vector>
using namespace std;
const int N = 2510;
int n, m, k;
long long sc[N];
int ver[20010], nxt[20010], head[20010], tot;
void add(int x, int y){
	ver[++tot] = y;
	nxt[tot] = head[x];
	head[x] = tot;
}
bool vis[N];
int dis[N][N];
vector<int> v[N];
bool cmp(int xx, int yy){
	return sc[xx] > sc[yy];
}
void bfs(int root){
	memset(vis, 0, sizeof(vis));
	queue<int> q;
	vis[root] = 1;
	dis[root][root] = 0;
	q.push(root);
	while(!q.empty()){
		int x = q.front();
		q.pop();
		for(int i = head[x]; i; i = nxt[i]){
			int y = ver[i];
			if(vis[y])
				continue;
			dis[root][y] = dis[root][x] + 1;
			if(y != 1 && root != 1 && dis[root][y] <= k + 1 && dis[1][y] <= k + 1){
				if(v[root].size() < 3)
					v[root].push_back(y);
				else{
					sort(v[root].begin(), v[root].end(), cmp);
					if(sc[y] > sc[v[root][2]])
						v[root][2] = y;
				}
			}
			vis[y] = 1;
			q.push(y);
		}
	}
}
long long ans;
bool same(int a, int b, int c, int d){
	if(a == b || a == c || a == d || b == c || b == d || c == d)
		return 1;
	return 0; 
}
long long count(int a, int b, int c, int d){
	if(same(a, b, c, d))
		return 0;
	return sc[a] + sc[b] + sc[c] + sc[d];
}
int main(){
	scanf("%d%d%d", &n, &m, &k);
	for(int i = 2; i <= n; i++)
		scanf("%d", &sc[i]);
	for(int i = 1; i <= m; i++){
		int x, y;
		scanf("%d%d", &x, &y);
		add(x, y);
		add(y, x);
	}
	memset(dis, 0x3f, sizeof(dis));
	for(int i = 1; i <= n; i++)
		bfs(i);
	for(int b = 2; b <= n; b++)
		for(int c = 2; c <= n; c++){
			if(dis[b][c] > k + 1)
				continue;
			for(int i = 0; i < v[b].size(); i++)
				for(int j = 0; j < v[c].size(); j++){
					int a = v[b][i], d = v[c][j];
					ans = max(ans, count(a, b, c, d));
				}
		}
	cout << ans << endl;
	return 0;
}