#include <bits/stdc++.h>

using namespace std;
using LL = long long;
using PII = pair<int , int>;

void solved() {
   int n , m , k , w;
   cin >> n >> m >> k >> w;

   map<int , int> mp;
   vector<int> a(n + m + 1);
   for(int i = 1 ; i <= n ; i ++ ){
       cin >> a[i];
       mp[a[i]] = 1;
   }
   for(int i = 1 ; i <= m ; i ++ ){
       cin >> a[i + n];
   }

    std::sort(a.begin(), a.end());
    for(int i = 1 ; i <= n + m ; i ++ )
        cout << a[i] << " \n"[i == n + m];
   vector<int> c;
   for(int i = 1 ; i <= n + m ; i ++ ){
       if(!mp[a[i]]) continue;
       int j = i , last = 0;
       while(j <= n + m && mp[a[j]]){
           if(a[j] > last) {
               last = a[j] + k - 1;
               c.push_back(a[j]);
           }
           j ++;
       }
       if(j <= n + m && last >= a[j]) {
           c[c.size() - 1] = a[j] - k;
           if(a[j] - k <= 0){
               cout << "-1\n";
               return;
           }
           for (int z = c.size() - 2; z >= 0; z--)
               if (c[z] + k - 1 >= c[z + 1]) {
                   c[z] = c[z + 1] - k;
                   if (c[z] <= a[i - 1]) {
                       cout << "-1\n";
                       return;
                   }
               } else break;
       }else if(j == n + m + 1 && last > w){
           c[c.size() - 1] = w - k + 1;
           if(w - k + 1 <= 0)
           for (int z = c.size() - 2; z >= 0; z--)
               if (c[z] + k - 1 >= c[z + 1]) {
                   c[z] = c[z + 1] - k;
                   if (c[z] <= a[i - 1]) {
                       cout << "-1\n";
                       return;
                   }
               } else break;
       }
//       cout << i << " " << j << " " << last << "\n";
       i = j;
   }

   cout << c.size() << "\n";
   for(int x : c) cout << x << " ";
   cout << "\n";
}

int main(){

    ios::sync_with_stdio(0);
    cin.tie(0);
    cout.tie(0);

    int t = 1;
    cin >> t;

    while(t -- )
        solved();

    return 0;
}