E

#pragma GCC optimzize("Ofast,no-stack-protector")
#include<bits/stdc++.h>
#define int long long
#define quick ios::sync_with_stdio(0);cin.tie(0);
#define rep(x,a,b) for(int x=a;x<=b;x++)
#define repd(x,a,b) for(int x=a;x>=b;x--)
#define lowbit(x) (x&-x)
#define sz(x) (int)(x.size())
#define F first
#define S second
#define all(x) x.begin(),x.end()
#define mp make_pair
#define eb emplace_back
using namespace std;
typedef pair<int,int> pii;
void debug(){
    cout<<"\n";
}
template <class T,class ... U >
void debug(T a, U ... b){
    cout<<a<<" ",debug(b...);
}
const int N=1e6+7;
const int INF=1e18;
int n,m,q,k;
vector<int> order;
bool vis[N];
int scc[N];
vector<int> v[N];
vector<int> v2[N];
int num=0;
int L[N];
int val[N];
int L2[N];
int d2[N];
vector<int> v3[N];
void Revdfs(int x){
    vis[x]=true;
    for(int i:v2[x]){
        if(!vis[i]){
            Revdfs(i);
        }
    }
    order.eb(x);
}
void dfs(int x){
    scc[x]=num;
    L[num]+=val[x];
    for(int i:v[x]){
        if(!scc[i]){
            dfs(i);
        }
    }
}
void Kosaraju(){
    num=0;
    order.clear();
    rep(i,1,n) vis[i]=false,L[i]=L2[i]=0,scc[i]=0,d2[i]=0;
    rep(i,1,n){
        if(!vis[i])Revdfs(i);
    }
    reverse(all(order));
    for(int i:order){
        if(!scc[i]) ++num,dfs(i);
    }
    rep(i,1,n){
        for(int j:v[i]){
            if(scc[j]!=scc[i]){
                v3[scc[j]].eb(scc[i]);
                d2[scc[i]]++;
            }
        }
    }
    //assert(num<=n);
}
struct edge{
    int f,to,k;
}e[N];
int a[N];
int x[N];
bool ok(int K){
    int ans=0;
    /*fill(v,v+n+1,vector<int>());
    fill(v2,v2+n+1,vector<int>());
    fill(v3,v3+n+1,vector<int>());*/
    rep(i,1,n) v[i].clear(),v2[i].clear(),v3[i].clear();
    rep(i,1,m){
        if(e[i].k<=K){
            v[e[i].f].eb(e[i].to);
            v2[e[i].to].eb(e[i].f);
        }
    }
    Kosaraju();
    queue<int> Q;
    rep(i,1,num){
        L2[i]=L[i];
        if(!d2[i]) Q.push(i);
    }
    while(Q.size()){
        int x=Q.front();
        Q.pop();
        for(int i:v3[x]){
            L2[i]=max(L2[i],L[i]+L2[x]);
            d2[i]--;
            if(!d2[i]) Q.push(i);
        }
    }
    rep(i,1,n) ans+=L2[scc[i]];
    return ans>=q;
}
signed main(){
    quick
    cin>>n>>m>>k>>q;
    int Kmax=0;
    rep(i,1,k) cin>>a[i];
    rep(i,1,k) cin>>x[i];
    rep(i,1,m){
        cin>>e[i].f>>e[i].to>>e[i].k;
        Kmax=max(Kmax,e[i].k);
    }
    rep(i,1,k){
        val[a[i]]=x[i];
    }
    if(ok(0)) cout<<0<<"\n";
    else if(!ok(Kmax)) cout<<"-1"<<"\n";
    else{
        int l=0;
        int r=Kmax;
        while(l+1<r){
            int middle=(l+r)>>1;
            if(ok(middle)) r=middle;
            else l=middle;
        }
        cout<<r<<"\n";
    }
    return 0;
}