1
3
5 3 4
 6
5
5 3 4 4 5
3
1 1 1
5
4 4 3 4 4
5
5 5 4 3 2
3
1 1 2
5
5 4 3 5 5
 1
3
10 1 5

1
 1
-1
2
2
3
1
 1

import jdk.jshell.EvalException;

import java.util.*;
import java.lang.*;
import java.io.*;

public class Solution {
    public static void main(String[] args) throws java.lang.Exception {
        out = new PrintWriter(new BufferedOutputStream(System.out));
        sc = new FastReader();
        int test = sc.nextInt();
        for (int t = 0; t < test; t++) {
            solve();
        }
        out.close();

    }

    private static void solve() {
        int n = sc.nextInt();
        int[] arr = new int[n];
        for (int i = 0; i < n; i++) {
            arr[i] = sc.nextInt();
        }
        Arrays.sort(arr);
        int i = n - 1;
        while (i > 0 && arr[i] == arr[i - 1]) {
            i--;
        }
        if (i == 0) {
            out.println(-1);
            return;
        }
        int res = i;
        for (int j = 1; j <= i; j++) {
            arr[j] += arr[j - 1];
        }
        for (int j = i + 1; j < n; j++) {
            if (arr[j] >= arr[j - 1]) {
                out.println(-1);
                return;
            }
            arr[j] += arr[j - 1];
        }
        out.println(i + 1);
    }

    public static FastReader sc;
    public static PrintWriter out;
    static class FastReader
    {
        BufferedReader br;
        StringTokenizer st;

        public FastReader()
        {
            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;
        }
    }
}

