#include <bits/stdc++.h>

#define int long long

using namespace std;

constexpr int INF = 1e9;

void solve(){
    int n,m,k,w;
    cin>>n>>m>>k>>w;
    //1 red, 2 black
    vector<array<int,2>> vec;
    for(int i=0;i<n;i++){
        int pos;
        cin>>pos;
        vec.push_back({pos,1});
    }
    for(int i=0;i<m;i++){
        int pos;
        cin>>pos;
        vec.push_back({pos,2});
    }
    vec.push_back({0,2});
    vec.push_back({w + 1,2});
    sort(vec.begin(),vec.end());
    vector<int> black;
    for(int i=0;i<vec.size();i++){
        if(vec[i][1] == 2){
            black.push_back(i);
        }
    }
    int ans = 0;
    vector<int> temp1,temp2;
    auto check = [&](int num,int l,int r){
        temp1.clear();
        temp2.clear();
        int res1=0;
        int i = l;
        int L  = -1;
        int blkr = vec[r + 1][0];
        int blkl = vec[l - 1][0];
        while(i <= r){
            auto [pos,col] = vec[i];
            if(L==-1){
                L = pos;
                temp1.push_back(L);
                res1++;
            } else {
                if(pos - L + 1 > k){
                    if(pos + k - 1 >= blkr){
                        if(L+k-1>=blkr - k){
                            res1 = INF;
                            break;
                        }
                        L = blkr - k;
                        temp1.push_back(L);
                        res1++;
                    }else{
                        L = pos;
                        temp1.push_back(L);
                        res1++;
                    }
                }
            }
            i++;
        }
        i = r;
        int R  = -1;
        int res2=0;
        while(i >= l){
            auto [pos,col] = vec[i];
            if(R==-1){
                if(pos - k + 1 <= blkl){
                    R = blkl + k;
                }else{
                    R = pos;
                }
                temp2.push_back(R-k+1);
                res2++;
            } else {
                if(R - pos + 1 > k){
                    if(pos - k + 1 <= blkl){
                        if(blkl + k >= R - k + 1){
                            res2 = INF;
                            break;
                        }
                        R = blkl + k;
                        temp2.push_back(R-k+1);
                        res2++;
                    }else{
                        R = pos;
                        temp2.push_back(R-k+1);
                        res2++;
                    }
                }
            }
            i--;
        }
        if(res1<res2){
            temp2.clear();
        }else{
            temp1.clear();
        }
        return min(res1,res2) <= num;
    };
    vector<int> op;
    for(int i=0;i<black.size() - 1;i++){
        int len = (vec[black[i+1]][0]-vec[black[i]][0]) - 1;
        int l = 0,r = len / k;
        while(l<r){
            int m = (l+r)/2;
            if(check(m,black[i]+1,black[i+1]-1)){
                r=m;
            }else{
                l=m+1;
            }
        }
        if(check(l,black[i]+1,black[i+1]-1)){
            op.insert(op.end(),temp1.begin(),temp1.end());
            op.insert(op.end(),temp2.begin(),temp2.end());
            ans+=l;
        }else{
            cout<<-1<<endl;
            return;
        }
    }
    cout << ans << endl;
    assert(ans==op.size());
    for(auto item:op){
        cout<<item<<" ";
        assert(item>=1&&item<=w);
    }
    cout<<endl;
}

signed main(){
    ios::sync_with_stdio(false);
    cin.tie(nullptr);
    cout.tie(nullptr);
    int t;
    cin >> t;
    while (t--){
      solve();
    }
}