#include <bits/stdc++.h>

using namespace std;
#define SZ(x) (int) (x).size()
#define REP(i, n) for(int i = 0; i < (n); i++)
#define FOR(i, a, b) for(auto i = (a); i < (b); i++)
#define For(i, a, b, c) \
	for(auto i = (a); i != (b); i += (c))
#define REPR(i, n) for(auto i = (n) - 1; i >= 0; i--)
#define ALL(s) (s).begin(), (s).end()
#define so(V) sort(ALL(V))
#define rev(V) reverse(ALL(V))
#define uni(v) v.erase(unique(ALL(v)), (v).end())
#define eb emplace_back

typedef unsigned long long ull;
typedef long long ll;
typedef vector<int> vi;
typedef vector<ll> vll;
typedef vector<bool> vb;
typedef vector<vi> vvi;
typedef vector<vll> vvll;
typedef pair<int, int> PI;
typedef pair<ll, ll> PL;
const double EPS = 1e-6;
const int MOD = 1e9 + 7;
const int INF = (1 << 30);
const ll LINF = 1e18;
const double math_PI = acos(-1);

template<typename T>
vector<T> make_v(size_t a) {
	return vector<T>(a);
}

template<typename T, typename... Ts>
auto make_v(size_t a, Ts... ts) {
	return vector<decltype(make_v<T>(ts...))>(
		a, make_v<T>(ts...));
}

template<typename T, typename V>
typename enable_if<is_class<T>::value == 0>::type fill_v(
	T &t, const V &v) {
	t = v;
}

template<typename T, typename V>
typename enable_if<is_class<T>::value != 0>::type fill_v(
	T &t, const V &v) {
	for(auto &e: t) fill_v(e, v);
}

template<class T>
bool chmax(T &a, const T &b) {
	if(a < b) {
		a = b;
		return true;
	}
	return false;
}

template<class T>
bool chmin(T &a, const T &b) {
	if(a > b) {
		a = b;
		return true;
	}
	return false;
}

template<typename S, typename T>
istream &operator>>(istream &is, pair<S, T> &p) {
	cin >> p.first >> p.second;
	return is;
}

template<typename T>
istream &operator>>(istream &is, vector<T> &vec) {
	for(T &x: vec) is >> x;
	return is;
}

template<typename T>
string join(vector<T> &vec, string splitter) {
	stringstream ss;
	REP(i, SZ(vec)) {
		if(i != 0) ss << splitter;
		ss << vec[i];
	}
	return ss.str();
}

template<typename T>
ostream &operator<<(ostream &os, vector<T> &vec) {
	os << join(vec, " ");
	return os;
}

#ifdef LOCAL
#include "./cpp-dump/dump.hpp"
#include "./cpp-dump/mytypes.hpp"
#define dump(...) cpp_dump(__VA_ARGS__)
namespace cp = cpp_dump;
#else
#define dump(...)
#define preprocess(...)
#define CPP_DUMP_SET_OPTION(...)
#define CPP_DUMP_DEFINE_EXPORT_OBJECT(...)
#define CPP_DUMP_DEFINE_EXPORT_ENUM(...)
#define CPP_DUMP_DEFINE_DANGEROUS_EXPORT_OBJECT(...)
#endif

void solve() {
	int N, M, K, W;
	cin >> N >> M >> K >> W;
	int preB = -1;
	vi vR(N), vB(M);
	cin >> vR >> vB;
	so(vR);
	so(vB);
	queue<int> R, B;
	REP(i, N) {
		vR[i]--;
		R.push(vR[i]);
	}
	REP(i, M) {
		vB[i]--;
		B.push(vB[i]);
	}
	B.push(W);
	int right = -1;

	vi ans;
	while(!B.empty()) {
		int len = B.front() - preB - 1;
		int cnt = 0;
		vi V;
		while(!R.empty() && R.front() <= B.front()) {
			int r = R.front();
			if(r <= right && r > preB) {
				R.pop();
				continue;
			}
			right = r + K - 1;
			cnt++;
			V.push_back(r + 1);
			if(cnt * K > len) {
				cout << -1 << endl;
				return;
			}
			R.pop();
		}
		REP(i, cnt) {
			int v = V[i];
			chmax(v, preB + 1 + i * K);
			chmin(v, B.front() - K * (cnt - i));
			ans.push_back(v + 1);
		}
		preB = B.front();
		B.pop();
	}
	cout << SZ(ans) << endl;
	cout << ans << endl;
}

int main() {
	cin.tie(nullptr);
	ios::sync_with_stdio(false);
	int T;
	cin >> T;
	while(T--) {
		solve();
	}
	return 0;
}