#include<bits/stdc++.h>
#define int long long
#define inf 0x3f3f3f3f3f3f3f 
#define GG ios::sync_with_stdio(false);cin.tie(0);cout.tie(0);
#define cnot cout<<"NO"<<"\n"
#define cyes cout<<"YES"<<"\n"
#define cans cout<<ans<<"\n"
#define pb push_back
#define x0 first
#define y0 second
#define lc p<<1
#define rc p<<1|1
#define mem(a,b) memset(a,b,sizeof(a))
using namespace std;
typedef pair<int,string>Pis;
typedef pair<int,int>Pii;
const int N=2e5+10,mod=1e9+7,M=1e6+10;
int lowbit(int x){
return x&(-x);}
int a[N],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);
    vector<Pii>op;
    vector<int>ans;
    int l=1,r;
    for(int i=1;i<=m;i++){
        if(b[i]==l){
            l=b[i]+1;
            continue;
        }
        if(b[i]==b[i-1]+1){
            continue;
        }
        r=b[i]-1;
        op.pb({l,r});
        l=r+2;
    }
    if(b[m]!=w){
    op.pb({l,w});
    }
    int sum=0;
     vector<int>s1,s2;
    int j=1;
    for(int i=0;i<op.size();i++){
        s1.clear();
        s2.clear();
        while(a[j]<=op[i].y0){
            s1.pb(a[j]);
            int o=a[j];
            while(a[j]<=o+k-1){
                j++;
            }
        }
        if(s1.back()+k-1<=op[i].y0){
            for(int ii=0;ii<s1.size();ii++){
                ans.pb(s1[ii]);
            }
            sum+=s1.size();
            continue;
        }
        int nn=s1.size(),cu=s1.back()+k-1-op[i].y0;
        for(int ii=nn-1;ii>=0;ii--){
            s2.pb(s1[ii]-cu);
            if(ii>=1)
            cu-=(s1[ii]-s1[ii-1]-k);
            else {
                cu-=(s1[ii]-op[i].x0);
            }
            cu=max(cu,0ll);
        }
        if(cu>0){
            cout<<-1<<"\n";
            return ;
        }
        for(int ii=nn-1;ii>=0;ii--){
            ans.pb(s2[ii]);
        }
        sum+=s2.size();
    }
    cout<<sum<<"\n";
    for(int i=0;i<ans.size();i++){
        cout<<ans[i]<<" ";
    }
    cout<<"\n";
}
signed main(){
    GG;
    int _t=1;
    cin>>_t;
    while(_t--){
        solve();
    }
    
}