
import java.io.BufferedReader;
import java.io.IOException;
import java.io.InputStreamReader;
import java.util.*;

public class OldFloppyDrive {

    public static void main(String[] args){
        MyScanner sc = new MyScanner();
        int t = sc.nextInt();
        while(t-->0){
            int n = sc.nextInt();
            int m = sc.nextInt();
            long[] arr = new long[n];
            long[] queries = new long[n];
            for(int i=0;i<n;i++){
                arr[i] = sc.nextLong();
            }
            for(int i=0;i<m;i++){
                queries[i] = sc.nextLong();
            }

            HashMap<Long,Long> mp = new HashMap<>();
            long acc = 0;
            for(long i=0;i<n;i++){
                acc += arr[(int)i];
                mp.put(acc,i);
            }
            mp.put(0l,-1l);
            ArrayList<Long> res = new ArrayList<>();
            for(int i=0;i<m;i++){
                if(acc == 0 || (acc < 0 && queries[i] >= 0) || (acc > 0 && queries[i] <= 0)){
                    if(mp.containsKey(queries[i])){
                        res.add(mp.get(queries[i]));
                    }else{
                        res.add(-1l);
                    }
                }else{
                    long cnt = (queries[i]/acc);
                    queries[i] -= acc*cnt;
                    if(mp.containsKey(queries[i])){
                        res.add((cnt*n) +mp.get(queries[i]));
                    }else{
                        res.add(-1l);
                    }
                }
            }
            for(int i=0;i<res.size();i++){
                System.out.print(res.get(i)+" ");
            }
            System.out.println();
        }
    }











    public static class MyScanner {
        BufferedReader br;
        StringTokenizer st;

        public MyScanner() {
            br = new BufferedReader(new InputStreamReader(System.in));
        }

        String next() {
            while (st == null || !st.hasMoreElements()) {
                try {
                    st = new StringTokenizer(br.readLine());
                } catch (IOException e) {
                    e.printStackTrace();
                }
            }
            return st.nextToken();
        }

        int nextInt() {
            return Integer.parseInt(next());
        }

        long nextLong() {
            return Long.parseLong(next());
        }

        double nextDouble() {
            return Double.parseDouble(next());
        }

        String nextLine(){
            String str = "";
            try {
                str = br.readLine();
            } catch (IOException e) {
                e.printStackTrace();
            }
            return str;
        }

    }

}
