#include <bits/stdc++.h>
#define endl '\n'
using namespace std;
typedef long long ll;
typedef pair<int,int>PII;
const int N = 2e5 + 10;
ll n, m, k, w, a[N], b[N];
void solve(){
    cin >> n >> m >> k >> w;
    for(int i = 1; i <= n; i ++ ){
        cin >> a[i];
    }
    b[1] = 0;
    for(int i = 2; i <= m + 1; i ++ ){
        cin >> b[i];
    }
    b[m + 2] = w + 1;
    m += 2;
    sort(a + 1, a + 1 + n);
    sort(b + 1, b + 1 + m);
    vector<ll> ans;
    for(int i = 1; i < m; i ++ ){
        int idl = lower_bound(a + 1, a + 1 + n, b[i]) - a;
        int idr = upper_bound(a + 1, a + 1 + n, b[i + 1]) - a - 1;
        if(idl > idr) continue;
        ll l = a[idl], r = l + k - 1, mc = a[idl] - b[i] - 1;
        ll c = max(0ll, r - b[i + 1] + 1);
        if(c > mc){
            cout << -1 << endl;
            return;
        }else{
            l -= c;
            r -= c;
            mc -= c;
        }
        ans.push_back(l);
        for(int j = idl + 1; j <= idr; j ++ ){
            if(a[j] <= r) continue;
            mc = max(mc,a[j] - r - 1);
            l = a[j], r = l + k - 1;
            c = max(0ll, r - b[i + 1] + 1);
            if(c > mc){
                cout << -1 << endl;
                return;
            }else{
                l -= c;
                r -= c;
                mc -= c;
            }
            ans.push_back(l);
        }
    }
    cout << ans.size() << endl;
    for(auto i : ans){
        cout << i << " ";
    }
    cout << endl;
}
int main(){
    ios::sync_with_stdio(0);
    cin.tie(0);
    cout.tie(0);
    int t=1;
    cin>>t;
    while(t--){
        solve();
    }
    return 0;
}