#include<bits/stdc++.h>
using namespace std;

const int N=1e6+5;
typedef long long ll;
typedef unsigned long long ull;
const ull P=133331;

struct SegT{
	int ls,rs;
	ll hash;
}t[N*4];
int f[N],tot,x[N],a[N],L,R,n,powP[N];
#define ls(p) (t[p].ls)
#define rs(p) (t[p].rs)
#define hsh(p) (t[p].hash)
void Update(int p,int l,int r){
	int mid=(l+r)/2;
	hsh(p)=hsh(ls(p))*powP[r-mid]+hsh(rs(p));
}
int Alloc(int cpy){return t[++tot]=t[cpy],tot;}
void Insert(int &p,int old,int l,int r,int x){
	p=Alloc(old);
	if(l==r) return hsh(p)++,void();
	int mid=(l+r)/2;
	if(x<=mid) Insert(ls(p),ls(old),l,mid,x);
	else	   Insert(rs(p),rs(old),mid+1,r,x);
	Update(p,l,r);
}
bool LessThan(int a,int b,int l,int r){
	if(hsh(a)==hsh(b)) return true;
	if(l==r) return hsh(a)<=hsh(b);
	int mid=(l+r)/2;
	if(hsh(rs(a))!=hsh(rs(b))) return LessThan(rs(a),rs(b),mid+1,r);
	else					   return LessThan(ls(a),ls(b),l,mid);
}
vector<int> ans;
void Output(int a,int l,int r){
	if(l==r){
		if(hsh(a)) for(int i=1;i<=hsh(a);i++) ans.push_back(l);
		return;
	}
	int mid=(l+r)/2;
	Output(rs(a),mid+1,r),Output(ls(a),l,mid);
}
void dp(){
	fill(f+1,f+1+n,-1),f[0]=0;
	deque<int> q;Insert(f[1],f[0],1,n,a[1]);
	auto add=[&](int i){
		while(!q.empty() and LessThan(f[q.back()],f[i],1,n)) q.pop_back();
		q.push_back(i);
	};
	q.push_back(1);int cur=2;
	for(int i=2;i<=n;i++){
		while(cur<i and x[cur]<x[i]-R) cur++;
		while(cur<i and (x[i]-R<=x[cur] and x[cur]<=x[i]-L)) add(cur++);
		while(!q.empty() and q.front()<x[i]-R) q.pop_front();
		if(!q.empty()) Insert(f[i],f[q.front()],1,n,a[i]);
	}
}
void Clear(){
	#define C(x) (memset(x,0,sizeof x))
	tot=0;
}
void Read(){
	Clear(),cin>>n>>L>>R,powP[0]=1;;
	for(int i=1;i<=n;i++) cin>>x[i];
	for(int i=1;i<=n;i++) cin>>a[i];
	for(int i=1;i<=n;i++) powP[i]=powP[i-1]*P;
}
int main(){
	ios::sync_with_stdio(false);
	int T;cin>>T;
	while(T--){
		Read(),dp();
		if(f[n]==-1) cout<<"-1\n";
		else{
			ans.clear();
			Output(f[n],1,n),cout<<ans.size()<<"\n";
			for(int i:ans) cout<<i<<" ";
			cout<<"\n";
		}
	}
}
/*FOOTNOTE
//tmp paste


*/