/*
 * Date Created : 17/2/2021
 * Have A Good Day !
 */

import java.io.OutputStream;
import java.io.IOException;
import java.io.InputStream;
import java.io.OutputStream;
import java.io.PrintWriter;
import java.io.BufferedWriter;
import java.util.InputMismatchException;
import java.io.IOException;
import java.io.Writer;
import java.io.OutputStreamWriter;
import java.io.InputStream;

/**
 * Built using CHelper plug-in
 * Actual solution is at the top
 *
 * @author arpit
 */
public class Main {
    public static void main(String[] args) {
        InputStream inputStream = System.in;
        OutputStream outputStream = System.out;
        FastReader in = new FastReader(inputStream);
        OutputWriter out = new OutputWriter(outputStream);
        GOldFloppyDrive solver = new GOldFloppyDrive();
        int testCount = Integer.parseInt(in.next());
        for (int i = 1; i <= testCount; i++)
            solver.solve(i, in, out);
        out.close();
    }
    
    static class GOldFloppyDrive {
        long[] prefix;
        
        int CHECK(long rem) {
            int ans = -1;
            int lt = 0, rt = prefix.length - 1;
            while (lt <= rt) {
                int mid = (lt + rt) >> 1;
                if (prefix[mid] >= rem) {
                    ans = mid;
                    rt = mid - 1;
                } else lt = mid + 1;
            }
            if (rem <= 0) return 0;
            return ans;
        }
        
        public void solve(int testNumber, FastReader r, OutputWriter out) {
            int n = r.nextInt();
            long m = r.nextLong();
            long[] arr = r.nextLongArray(n);
            prefix = new long[n];
            long sum = 0L, max_sum = arr[0];
            for (int i = 0; i < n; i++) {
                sum += arr[i];
                max_sum = Math.max(max_sum, sum);
                prefix[i] = sum;
            }
            for (int i = 1; i < n; i++) prefix[i] = Math.max(prefix[i - 1], prefix[i]);
//        out.debugln("prefix", prefix);
            for (int i = 1; i <= m; i++) {
                long x = r.nextLong();
                if (prefix[n - 1] <= 0) out.print(-1, "");
                else {
                    long complete = Math.max(0L, (long) Math.ceil(((double) x - max_sum) / sum));
                    long rem = Math.max(0L, CHECK((x - (complete * sum))));
                    out.print(((complete * n) + rem), "");
                }
            }
            out.println();
        }
        
    }
    
    static class FastReader {
        private InputStream stream;
        private byte[] buf = new byte[1024];
        private int curChar;
        private int numChars;
        private FastReader.SpaceCharFilter filter;
        
        public FastReader(InputStream stream) {
            this.stream = stream;
        }
        
        public int read() {
            if (numChars == -1) {
                throw new InputMismatchException();
            }
            if (curChar >= numChars) {
                curChar = 0;
                try {
                    numChars = stream.read(buf);
                } catch (IOException e) {
                    throw new InputMismatchException();
                }
                if (numChars <= 0) {
                    return -1;
                }
            }
            return buf[curChar++];
        }
        
        public int nextInt() {
            int c = read();
            while (isSpaceChar(c)) {
                c = read();
            }
            int sgn = 1;
            if (c == '-') {
                sgn = -1;
                c = read();
            }
            int res = 0;
            do {
                if (c < '0' || c > '9') {
                    throw new InputMismatchException();
                }
                res *= 10;
                res += c - '0';
                c = read();
            } while (!isSpaceChar(c));
            return res * sgn;
        }
        
        public long nextLong() {
            int c = read();
            while (isSpaceChar(c)) {
                c = read();
            }
            int sgn = 1;
            if (c == '-') {
                sgn = -1;
                c = read();
            }
            long res = 0;
            do {
                if (c < '0' || c > '9') {
                    throw new InputMismatchException();
                }
                res *= 10;
                res += c - '0';
                c = read();
            } while (!isSpaceChar(c));
            return res * sgn;
        }
        
        public String nextString() {
            int c = read();
            while (isSpaceChar(c)) {
                c = read();
            }
            StringBuilder res = new StringBuilder();
            do {
                if (Character.isValidCodePoint(c)) {
                    res.appendCodePoint(c);
                }
                c = read();
            } while (!isSpaceChar(c));
            return res.toString();
        }
        
        public boolean isSpaceChar(int c) {
            if (filter != null) {
                return filter.isSpaceChar(c);
            }
            return isWhitespace(c);
        }
        
        public static boolean isWhitespace(int c) {
            return c == ' ' || c == '\n' || c == '\r' || c == '\t' || c == -1;
        }
        
        public String next() {
            return nextString();
        }
        
        public long[] nextLongArray(int n) {
            long[] array = new long[n];
            for (int i = 0; i < n; ++i) array[i] = nextLong();
            return array;
        }
        
        public interface SpaceCharFilter {
            public boolean isSpaceChar(int ch);
            
        }
        
    }
    
    static class OutputWriter {
        private final PrintWriter writer;
        
        public OutputWriter(OutputStream outputStream) {
            writer = new PrintWriter(new BufferedWriter(new OutputStreamWriter(outputStream)));
        }
        
        public OutputWriter(Writer writer) {
            this.writer = new PrintWriter(writer);
        }
        
        public void print(Object... objects) {
            for (int i = 0; i < objects.length; i++) {
                writer.print(objects[i]);
                if (i != objects.length - 1) writer.print(" ");
            }
        }
        
        public void println() {
            writer.println();
        }
        
        public void close() {
            writer.close();
        }
        
    }
}

