#define _CRT_SECURE_NO_WARNINGS
#include<bits/stdc++.h>
#define int long long
#define YES cout<<"YES\n"
#define NO cout<<"NO\n"
#define endl "\n"
#define debug cout<<'*'<<'\n'
const int N = 2e5 + 500, M = 5e5 + 500;
const int mod = 1e9 + 7, inf = 0x3f3f3f3f3f3f3f3f;
using namespace std;

int a[N];
int b[N];
void solve()
{
    int n,m,k,w;
    cin>>n>>m>>k>>w;
    for(int i=1;i<=n;i++)cin>>a[i];
    for(int i=1;i<=m;i++)cin>>b[i];
    sort(a+1,a+1+n);
    sort(b+1,b+1+m);
    b[++m]=w+1;
    b[0]=0;
    //for(int i=1;i<=n;i++)cout<<a[i]<<" ";cout<<endl;
    //for(int i=1;i<=m;i++)cout<<b[i]<<" ";cout<<endl;
    vector<int> ans,tmp;
    int cnt=0,les=0,f=1;
    for(int i=1,j=1;i<=n&&j<=m;) {
        if(a[i]>b[j]) {
            if(cnt*k>b[j]-b[j-1]-1) {
                //cout<<i<<" "<<j<<" "<<cnt<<endl;
                cout<<-1<<endl;
                return;
            }
            for(int w=tmp.size()-1;w>=0;w--) {
                if(w==tmp.size()-1) tmp[w]-=max(0ll,tmp[w]+k-b[j]);
                else tmp[w]-=max(0ll,tmp[w]+k-tmp[w+1]);
            }
            for(int x:tmp)ans.push_back(x);
            tmp.clear();
            cnt=les=0;
            f=1;
            j++;
            continue;
        }
        if(!f) {
            if(les>=a[i]-a[i-1])
                les-=a[i]-a[i-1];
            else{
                tmp.push_back(a[i]);
                cnt++;
                les=k-1;
            }
        }else {
            f=0;
            tmp.push_back(a[i]);
            cnt++;
            les=k-1;
        }
        //cout<<i<<" "<<cnt<<" "<<les<<endl;
        i++;
    }
    if(tmp.size()) {
        if(cnt*k>b[m]-b[m-1]-1) {
            //cout<<i<<" "<<j<<" "<<cnt<<endl;
            cout<<-1<<endl;
            return;
        }
        for(int w=tmp.size()-1;w>=0;w--) {
            if(w==tmp.size()-1) tmp[w]-=max(0ll,tmp[w]+k-b[m]);
            else tmp[w]-=max(0ll,tmp[w]+k-tmp[w+1]);
        }
        for(int x:tmp)ans.push_back(x);
        tmp.clear();
        cnt=les=0;
        f=1;
    }
    cout<<ans.size()<<"\n";
    for(int x:ans)cout<<x<<" ";cout<<"\n";
}
signed main()
{
   // freopen("C:\\Users\\win11\\Desktop\\test.txt", "r", stdin);
    ios::sync_with_stdio(false);
    cin.tie(0);
    cout.tie(0);

    int T = 1;
    cin >> T;
    while (T--)solve();
}