#include <bits/stdc++.h>
using namespace std;
struct edge{
	unsigned long long u,to;
}e[7000005];
unsigned long long n,m,k,x,y,val[2505],dis[2505][2505],cnt=0,maxx=0,pos[2505][4];
vector<unsigned long long>v[2505];
void bfs(unsigned long long beg){//cout<<"g"<<endl;
	queue<int>q;
	q.push(beg);
	dis[beg][beg]=0;
	while(!q.empty()){
		unsigned long long u=q.front();
		q.pop();
		for(unsigned long long i=0;i<v[u].size();i++){
			unsigned long long to=v[u][i];
			if(dis[beg][to]==dis[0][0]){
				dis[beg][to]=dis[beg][u]+1;
				q.push(to);
			}
		}
	}	
}
int main(){
	ios::sync_with_stdio(false);cin.tie(0);cout.tie(0);
	for(int i=0;i<=2501;i++){
		for(int j=0;j<=2501;j++){
			dis[i][j]=4e18+5;
		}
	}
	cin>>n>>m>>k;
	for(unsigned long long i=2;i<=n;i++){
		cin>>val[i];
	}
	for(unsigned long long i=1;i<=m;i++){
		cin>>x>>y;
		v[x].push_back(y);
		v[y].push_back(x);
	}
	for(unsigned long long i=1;i<=n;i++){
		bfs(i);
	}
	for(int i=2;i<=n;i++){
		pos[i][0]=pos[i][1]=pos[i][2]=pos[i][3]=i;
		int maxx1=0,st1=-1,maxx2=0,st2=-1,maxx3=0,st3=-1,maxx4=0,st4=-1;
		for(int j=2;j<=n;j++){
			if(j==i) continue;
			if(dis[1][j]<=k+1&&dis[j][i]<=k+1&&val[j]>maxx1){
				maxx1=val[j];
				st1=j;
			}
		}
		for(int j=2;j<=n;j++){
			if(j==i||j==st1) continue;
			if(dis[1][j]<=k+1&&dis[j][i]<=k+1&&val[j]>maxx2){
				maxx2=val[j];
				st2=j;
			}
		}
		for(int j=2;j<=n;j++){
			if(j==i||j==st1||j==st2) continue;
			if(dis[1][j]<=k+1&&dis[j][i]<=k+1&&val[j]>maxx3){
				maxx3=val[j];
				st3=j;
			}
		}
		for(int j=2;j<=n;j++){
			if(j==i||j==st1||j==st2||j==st3) continue;
			if(dis[1][j]<=k+1&&dis[j][i]<=k+1&&val[j]>maxx4){
				maxx4=val[j];
				st4=j;
			}
		}
		if(st1!=-1) pos[i][0]=st1;
		if(st2!=-1) pos[i][1]=st2;
		if(st3!=-1) pos[i][2]=st3;
		if(st4!=-1) pos[i][3]=st4;
	}
	for(int i=2;i<=n;i++){
		for(int j=2;j<=n;j++){
			if(i!=j&&dis[i][j]<=k+1){
				for(int ii=0;ii<4;ii++){
					for(int jj=0;jj<4;jj++){
						if(i!=pos[i][ii]&&i!=pos[j][jj]&&pos[i][ii]!=pos[j][jj]&&pos[i][ii]!=j&&pos[j][jj]!=j){
							maxx=max(maxx,val[i]+val[j]+val[pos[i][ii]]+val[pos[j][jj]]);
						}
					}
				}
			}
		}
	}
	cout<<maxx;

	return 0;
}