#include<bits/stdc++.h>
#define int long long
using namespace std;
int a[1000010];
long long cost[1000010];
int n,m,k;
int check(int maxx){
	long long ans=0;
	for(int i=1;i<=(n+1)/2;++i){
		if(a[i]<=maxx)continue;
		int t=-1;
		if(a[i]%(maxx+1)==0)t=a[i]/(maxx+1);
		else t=a[i]/(maxx+1)+1;
		ans+=cost[t];
	}
	if(ans<=k)return 1;
	else return 0;
}
void solve(){
	
	cin>>n>>m>>k;
	for(int i=1;i<=n;++i)
		cin>>a[i];
	sort(a+1,a+n+1);
	for(int i=1;i<=m;++i)
		cin>>cost[i];
	for(int i=2;i*i<=m;++i){
		for(int j=2;j*j<=i;++j){
			if(i%j==0){
				cost[i]=min(cost[i],cost[j]*cost[i/j]);
			}
		}
	}
	priority_queue<pair<int,int> >q;
	for(int i=2;i*i<=m;++i){
		int t=(sqrt(m))/i*i;
		if(t<sqrt(m))t+=i;
		q.push(make_pair(-t,i));
	}
	while(!q.empty()){
		int bu=q.top().second,now=-q.top().first;
		q.pop();
		if(now>m)continue;
		cost[now]=min(cost[now],cost[now/bu]*cost[bu]);
		q.push(make_pair(-(now+bu),bu));
	}
	/*
	for(int i=1;i<=m;++i)
		cout<<cost[i]<<" ";cout<<"\n";
	*/
	for(int i=m-1;i>=1;--i)
		cost[i]=min(cost[i],cost[i+1]);
	cost[m+1]=0x3f3f3f3f3f3f;
	
	long long anss=0;
	for(int i=1;i<=(n+1)/2;++i){
		anss+=cost[a[i]+1];
	}
	if(anss<=k){
		cout<<"0\n";return;
	}
	int l=1,r=a[(n+1)/2],ans=-1;
	while(l<=r){
		int mid=(l+r)>>1;
	//	cout<<mid<<"!!!!\n";
		if(check(mid)){
			ans=mid;r=mid-1;
		}
		else l=mid+1;
	}
	cout<<ans<<"\n";
	//clear();
}
signed main(){
	ios::sync_with_stdio(false);
	cin.tie(0);
	int t;cin>>t;
	while(t--){
		solve();
	}
	return 0;
}