Paprika loves permutations. She has an array a_1, a_2, ..., a_n. She wants to make the array a permutation of integers 1 to n.

In order to achieve this goal, she can perform operations on the array. In each operation she can choose two integers i (1 ≤ i ≤ n) and x (x > 0), then perform a_i := a_i mod x (that is, replace a_i by the remainder of a_i divided by x). In different operations, the chosen i and x can be different.

Determine the minimum number of operations needed to make the array a permutation of integers 1 to n. If it is impossible, output -1.

A permutation is an array consisting of n distinct integers from 1 to n in arbitrary order. For example, [2,3,1,5,4] is a permutation, but [1,2,2] is not a permutation (2 appears twice in the array) and [1,3,4] is also not a permutation (n=3 but there is 4 in the array).

Input

Each test contains multiple test cases. The first line contains a single integer t (1 ≤ t ≤ 10^4) — the number of test cases. Description of the test cases follows.

The first line of each test case contains an integer n (1 ≤ n ≤ 10^5).

The second line of each test case contains n integers a_1, a_2, ..., a_n. (1 ≤ a_i ≤ 10^9).

It is guaranteed that the sum of n over all test cases does not exceed 2 ⋅ 10^5.

Output

For each test case, output the minimum number of operations needed to make the array a permutation of integers 1 to n, or -1 if it is impossible.

Example

Input


4
2
1 7
3
1 5 4
4
12345678 87654321 20211218 23571113
9
1 2 3 4 18 19 5 6 7


Output


1
-1
4
2

Note

For the first test, the only possible sequence of operations which minimizes the number of operations is: 

  * Choose i=2, x=5. Perform a_2 := a_2 mod 5 = 2. 



For the second test, it is impossible to obtain a permutation of integers from 1 to n.
8
2
2 3
3
3 4 5
1
1
1
2
1
3
1
4
1
12071207
5
5 5 5 9 14

1
2
0
-1
1
1
1
4

import javafx.scene.layout.Priority;
import sun.reflect.generics.tree.Tree;

import java.sql.Array;
import java.util.*;
import java.io.*;
import java.util.stream.Stream;

import static java.lang.Math.*;
public class B
{
    static InputReader in=new InputReader(System.in);
    static OutputWriter out=new OutputWriter(System.out);
    static StringBuilder sb=new StringBuilder();
    static long MOD = (long)(998244353);

    static int MAX = 3 * 100000 + 1;

    // Main Class Starts Here
    public static void main(String args[])throws IOException
    {
        // Write your code.
        int t = in();
        while(t-->0) {
            int n = in();
            int a[] = an(n);
            Arrays.sort(a);
            boolean isDone[] = new boolean[n+1];
            boolean used[] = new boolean[n];
            for(int i = 0; i < n; i++){
                if(a[i] <= n && !isDone[a[i]]){
                    isDone[a[i]] = true;
                    used[i] = true;
                }
            }

            int number = 1;
            int index = 0;
            int ans = 0;
            while(number <= n && index < n){
                if(isDone[number]){
                    number++;
                    continue;
                }
                while(index < n && used[index])
                    index++;
                // now see if this number can be generated by this index.
                while(index < n){
                    int temp = a[index] / 2;
                    if(a[index] % 2 == 0){
                        temp--;
                    }
                    if(temp >= number){
                        ans++;
                        used[index] = true;
                        isDone[number] = true;
                        break;
                    }
                    index++;
                }
            }
            if(number > n){
                app(ans+"\n");
            }
            else{
                app(-1+"\n");
            }
        }
        out.printLine(sb);
        out.close();
    }

    static class Pair{
        int x,y;
        Pair(int x, int y){
            this.x = x;
            this.y = y;
        }
    }

    public static int countDup(String str){
        int n = str.length();
        int count = 0;
        for(int i = 1; i < n; i++){
            char cur = str.charAt(i);
            char prev = str.charAt(i-1);
            if(cur == prev)
                count++;
        }
        return count;
    }

    public static String generateString(char a[], int n){
        for(int i = 1; i < n; i++){
            if(a[i] == '?'){
                if(a[i-1] == 'R')
                    a[i] = 'B';
                else
                    a[i] = 'R';
            }
            else{
                continue;
            }
        }
        String str = "";
        for(char x: a)
            str += x;
        return str;
    }

    static class DisjointSet{
        int par[];
        int rank[];
        int n;
        public DisjointSet(int n){
            this.n = n;
            par = new int[n];
            rank = new int[n];
            for(int i = 0; i < n; i++){
                par[i] = i;
            }
        }

        public int findPar(int i){
            // path compression.
            if(par[i] != i){
                par[i] = findPar(par[i]);
            }
            return par[i];
        }

        public int merge(int x, int y){
            int parX = findPar(x);
            int parY = findPar(y);
            if(parX == parY) return 0; // no decrease in connected components
            if(rank[parX] > rank[parY]){
                // merge y to x.
                par[parY] = parX;
            }
            else if(rank[parY] > rank[parX]){
                par[parX] = parY;
            }
            else{
                par[parY] = parX;
                rank[parX]++;
            }
            return 1; // after merging the decrease in connected components is 1.
        }
    }

    public static class Edge{
        int from;
        int to;
        int id;
        boolean visited;
        public Edge(int from, int to, int id){
            this.from = from;
            this.to = to;
            this.id =id;
            this.visited = false;
        }
    }

    public static int[] an(int n) {
        int ar[]=new int[n];
        for(int i=0;i<n;i++)
            ar[i]=in();
        return ar;
    }

    public static long[] lan(int n) {
        long ar[]=new long[n];
        for(int i=0;i<n;i++)
            ar[i]=lin();
        return ar;
    }

    public static String atos(Object ar[]) {
        return Arrays.toString(ar);
    }

    public static int in() {
        return in.readInt();
    }

    public static long lin() {
        return in.readLong();
    }

    public static String sn() {
        return in.readString();
    }

    public static void prln(Object o) {
        out.printLine(o);
    }

    public static void prn(Object o) {
        out.print(o);
    }

    public static void display(int a[]) {
        out.printLine(Arrays.toString(a));
    }

    public static HashMap<Integer,Integer> hm(int a[]){
        HashMap<Integer,Integer> map=new HashMap<>();
        for(int i=0; i < a.length;i++) {
            int keep = (int)map.getOrDefault(a[i],0);
            map.put(a[i],++keep);
        }
        return map;
    }

    public static void app(Object o) {
        sb.append(o);
    }

    public static long calcManhattanDist(int x1,int y1,int x2,int y2) {
        long xa = Math.abs(x1-x2);
        long ya = Math.abs(y1-y2);
        return (xa+ya);
    }


    static class InputReader {
        private InputStream stream;
        private byte[] buf = new byte[1024];
        private int curChar;
        private int numChars;
        private SpaceCharFilter filter;

        public InputReader(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 readInt() {
            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 readLong() {
            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 readString() {
            int c = read();
            while (isSpaceChar(c))
                c = read();
            StringBuilder res = new StringBuilder();
            do {
                res.appendCodePoint(c);
                c = read();
            } while (!isSpaceChar(c));
            return res.toString();
        }

        public boolean isSpaceChar(int c) {
            if (filter != null)
                return filter.isSpaceChar(c);
            return c == ' ' || c == '\n' || c == '\r' || c == '\t' || c == -1;
        }

        public String next() {
            return readString();
        }

        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++) {
                if (i != 0)
                    writer.print(' ');
                writer.print(objects[i]);
            }
        }

        public void printLine(Object...objects) {
            print(objects);
            writer.println();
        }

        public void close() {
            writer.close();
        }
    }
}