#include<iostream>
#include<cstdio>
#include<cstring>
#include<algorithm>
#include<vector>
#include<queue>

#define ll long long
#define MAXN 2500
#define MAXM 10000

using namespace std;

int n,m,k;//0<=k<=100
int x,y;
ll w[MAXN+1];
int dis[MAXN+1];
bool connected[MAXN+1][MAXN+1];
vector<int> edge[MAXN+1];
struct node{
	int num,dis;
	bool operator<(const node &tmp)const{
		return dis>tmp.dis;
	}
};
vector<int> f[MAXN+1];
ll ans;

inline ll read(){
	ll x=0,f=1; char ch=getchar();
	while(ch<'0'||ch>'9') ch=='-'?f=-f:false;
	while(ch>='0'&&ch<='9'){
		x=x*10+ch-'0';
		ch=getchar();
	}
	return x*f;
}

bool cmp(int a, int b){
	return w[a]>w[b];
}

void dijkstra(int x){
	memset(dis,-1,sizeof(dis));
	dis[x]=0;
	queue<node> q;
	q.push(node{x,0});
	node u;
	while(!q.empty()){
		u=q.front();
		q.pop();
		if(u.num!=x){
			connected[x][u.num]=true;
			if(x!=1&&connected[1][u.num]){
				f[x].push_back(u.num);
				sort(f[x].begin(),f[x].end(),cmp);
				if(f[x].size()>3){
					f[x].pop_back();
				}
			}
		}
		if(u.dis==k+1) continue;
		for(int i=0;i<edge[u.num].size();i++){
			if(dis[edge[u.num][i]]==-1){
				dis[edge[u.num][i]]=dis[u.num]+1;
				q.push(node{edge[u.num][i],dis[edge[u.num][i]]});
			}
		}
	}
}

int main(){
	n=read(); m=read(); k=read();
	for(int i=2;i<=n;i++){
		w[i]=read();
	}
	for(int i=1;i<=m;i++){
		x=read(); y=read();
		edge[x].push_back(y);
		edge[y].push_back(x);
	}
	for(int i=1;i<=n;i++) dijkstra(i);
	for(int B=2;B<=n;B++){
		for(int C=2;C<=n;C++){
			if(connected[B][C]){
				for(int i=0;i<f[B].size();i++){
					for(int j=0;j<f[C].size();j++){
						int A=f[B][i],D=f[C][j];
						if(A!=C&&B!=D&&A!=D){
							ans=max(ans,w[A]+w[B]+w[C]+w[D]);
						}
					}
				}
			}
		}
	}
	printf("%lld\n",ans);
}

subtask#0全AC subtask#1部分TLE subtask#2全TLE