#include <bits/stdc++.h>
using namespace std;
#define int long long
void solve()
{
    int n, m, k, w;
    cin >> n >> m >> k >> w;
    vector<int> a(n + 10), b(m + 10);
    for (int i = 1; i <= n; i++)
    {
        cin >> a[i];
    }
    for (int i = 1; i <= m; i++)
        cin >> b[i];
    b[++m] = w + 1;
    sort(a.begin() + 1, a.begin() + n + 1);
    sort(b.begin() + 1, b.begin() + m + 1);
    int flag = 1;
    vector<int> e;
    auto check = [&](int l, int r) -> int
    {
        vector<int> q;
        q.push_back(l - k + 1);
        int cnt = 0;
        int k1 = lower_bound(a.begin() + 1, a.begin() + n + 1, l) - a.begin();
        int kk = lower_bound(a.begin() + 1, a.begin() + n + 1, r) - a.begin();
        if (k1 == n + 1)
            return 0;
        int sum = 0;
        for (int i = k1; i < kk; i++)
        {
            if (l >= a[i])
                continue;
            if (a[i] + k - 1 < r)
                sum += a[i] - l - 1, l = a[i] + k - 1, cnt++, q.push_back(a[i]);
            if (a[i] + k - 1 >= r)
            {
                int w = a[i] + k - 1 - r + 1;
                if (sum >= w)
                {
                    sum -= w, l = r - 1, cnt++;
                    int len = q.size() - 1;
                    int pos;
                    for (int j = len; j >= 1; j--)
                    {
                        if (q[j] - (q[j - 1] + k - 1) - 1 >= w)
                        {
                            q[j] -= w;
                            pos = j;
                            break;
                        }
                        else
                        {
                            w -= q[j] - (q[j - 1] + k - 1) - 1;
                            q[j] = q[j - 1] + k;
                        }
                    }
                    for (int j = pos + 1; j <= len; j++)
                        q[j] = q[j - 1] + k;
                    q.push_back(r - k);
                }
                else
                {
                    flag = 0;
                    return 0;
                }
            }
        }
        if (!q.empty())
        {
            for(int i=1;i<q.size();i++)  e.push_back(q[i]);
        }
        return cnt;
    };
    int ans = 0;
    b[0] = 0;
    for (int i = 1; i <= m; i++)
    {
        ans += check(b[i - 1], b[i]);
        if (flag == 0)
        {
            cout << "-1" << '\n';
            return;
        }
    }
    if (w != b[m])
        ans += check(b[m], w + 1);
    if (flag == 0)
    {
        cout << "-1" << '\n';
        return;
    }
    cout << ans << '\n';
    for (auto x : e)
        cout << x << ' ';
    cout << '\n';
}
signed main()
{
    ios::sync_with_stdio(false);
    cin.tie(0), cout.tie(0);
    int t = 1;
    cin >> t;
    while (t--)
        solve();
    return 0;
}