import java.io.*;
import java.util.ArrayList;
import java.util.StringTokenizer;

public class Main {
    private static ArrayList<Long> list = new ArrayList<>();
    public static void main(String[] args) throws IOException {
        Scanner sc = new Scanner(System.in);
        int t = sc.nextInt();
        for (int i = 0; i < t; i++){
            int n = sc.nextInt();
            long m = sc.nextLong();
            long [] data = new long[n];
            for (int j = 0; j < n; j++){
                data[j] = sc.nextLong();
            }
            long num = 0;
            long answer = -1;
            boolean flag = false;
            //first walk
            for (int j = 0; j < n; j++){
                num+=data[j];
                if (num >= m){
                    answer = 1;
                    flag = true;
                    break;
                }
                if (num < 0){
                    num = 0;
                }
            }
            long firstWalk = num;
            //second walk
            long maximumReach = num;
            if (!flag){
                for (int j = 0; j < n; j++){
                    num+=data[j];
                    if (num >= m){
                        answer = 2;
                        flag = true;
                        break;
                    }
                    if (num < 0){
                        num = 0;
                    }
                    maximumReach = Math.max(num,maximumReach);
                }
            }
            if (!flag){
                if (num > firstWalk){
                    long addition = num - firstWalk;
                    maximumReach -= num;
                    answer = (m - firstWalk - maximumReach)/addition;
                    answer++;
                    if ((m - firstWalk - maximumReach)%addition > 0 ){
                    answer++;
                    }
                }
            }
            list.add(answer);
        }
        for (int i = 0; i < list.size(); i++){
            System.out.println(list.get(i));
        }
    }

    static public class Scanner {
        StringTokenizer st;
        BufferedReader br;

        public Scanner(InputStream s) {
            br = new BufferedReader(new InputStreamReader(s));
        }
        public String next() throws IOException {
            while (st == null || !st.hasMoreTokens())
                st = new StringTokenizer(br.readLine());
            return st.nextToken();
        }
        public Scanner(String s) throws FileNotFoundException {
            br = new BufferedReader(new FileReader(s));
        }
        public int nextInt() throws IOException {
            return Integer.parseInt(next());
        }

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

    }

}