You are given a non-decreasing array of non-negative integers a_1, a_2, …, a_n. Also you are given a positive integer k.

You want to find m non-decreasing arrays of non-negative integers b_1, b_2, …, b_m, such that:

  * The size of b_i is equal to n for all 1 ≤ i ≤ m. 
  * For all 1 ≤ j ≤ n, a_j = b_{1, j} + b_{2, j} + … + b_{m, j}. In the other word, array a is the sum of arrays b_i. 
  * The number of different elements in the array b_i is at most k for all 1 ≤ i ≤ m. 



Find the minimum possible value of m, or report that there is no possible m.

Input

The first line contains one integer t (1 ≤ t ≤ 100): the number of test cases.

The first line of each test case contains two integers n, k (1 ≤ n ≤ 100, 1 ≤ k ≤ n).

The second line contains n integers a_1, a_2, …, a_n (0 ≤ a_1 ≤ a_2 ≤ … ≤ a_n ≤ 100, a_n > 0).

Output

For each test case print a single integer: the minimum possible value of m. If there is no such m, print -1.

Example

Input


6
4 1
0 0 0 1
3 1
3 3 3
11 3
0 1 2 2 3 3 3 4 4 4 4
5 3
1 2 3 4 5
9 4
2 2 3 5 7 11 13 13 17
10 7
0 1 1 2 3 3 4 5 5 6


Output


-1
1
2
2
2
1

Note

In the first test case, there is no possible m, because all elements of all arrays should be equal to 0. But in this case, it is impossible to get a_4 = 1 as the sum of zeros.

In the second test case, we can take b_1 = [3, 3, 3]. 1 is the smallest possible value of m.

In the third test case, we can take b_1 = [0, 1, 1, 1, 2, 2, 2, 2, 2, 2, 2] and b_2 = [0, 0, 1, 1, 1, 1, 1, 2, 2, 2, 2]. It's easy to see, that a_i = b_{1, i} + b_{2, i} for all i and the number of different elements in b_1 and in b_2 is equal to 3 (so it is at most 3). It can be proven that 2 is the smallest possible value of m.
    import java.io.*;
    import java.io.IOException;
    import java.math.BigInteger;
    import java.util.*;





        //import javafx.util.Pair; 
        //import java.util.concurrent.LinkedBlockingDeque;







            
         public class Codeforces {
            
                
                public static long mod = 1000000007 ;
                public static double epsilon=0.00000000008854;//value of epsilon
                public static InputReader sc = new InputReader(System.in);
                public static PrintWriter pw = new PrintWriter(System.out);
                
                public static long pow(long x,long y,long mod){
                    long ans=1;
                    
                    x%=mod;
                    while(y>0){
                        if((y&1)==1){
                            ans=(ans*x)%mod;
                        }
                        y=y>>1;
                        x=(x*x)%mod;
                    }
                    return ans;
                }
                public static ArrayList<ArrayList <Pair>> GetGraph(int n,int m,HashSet<Integer> h){
                    ArrayList<ArrayList <Pair>> a=new ArrayList<>();
                    for(int i=0;i<n;i++){
                        a.add(new ArrayList<>());
                    }
                    for(int i=0;i<m;i++){
                        int u=sc.nextInt()-1;
                        int v=sc.nextInt()-1;
                        if(h.contains(v)){
                            h.remove(v);
                        }
                        a.get(u).add(new Pair(v, 0));
                        //a.get(v).add(new Pair(u, 1));
                    } 
                    return a;
                }
               
                public static int firstNode(int a,int p[]){
                    if(a!=p[a]){
                        p[a]=firstNode(p[a], p);
                    }
                    return p[a];
                }
                public static void Union(int a,int b,int p[]){
                    //int a=firstNode(a1, p);
                    //int b=firstNode(b1, p);
                    /*if(a!=b){
                        if(r[a]<r[b]){
                            p[a]=b;
                        }
                        else if(r[a]>r[b]){
                            p[b]=a;
                        }
                        else{
                            r[b]++;
                            p[a]=b;
                        }
                    }*/
                    if(a!=b)
                    p[firstNode(a,p)]=firstNode(b,p);//if no rank than 
                }
            
               public static boolean check(int m,int k,int a[]){
                   int n=a.length;
                   int c=1;int t=0;;
                   for(int i=1;i<n;i++){
                    if(a[i]==a[i-1])continue;
                    t++;
                    if(t==1)
                    {
                        //t=0;
                        c++;
                    }
                    if(t==m)t=0;
                   }
                   if(c>k) return false;
                   else return true;

               }

                public static void main(String[] args) throws Exception {
                    // code starts.
                   int q=sc.nextInt();
                   while(q-->0){
                       int n=sc.nextInt();
                       int k=sc.nextInt();
                       int a[]=scanArray(n);int ans=-1;
                        for(int i=1;i<=100;i++){
                            if(check(i, k, a)){
                                ans=i;
                                break;
                            }
                            
                        }
                        pw.println(ans);
                   }
                   
                    // Code ends...
                    pw.flush();
                    pw.close();
                }
                public static Comparator<Integer[]> MOquery(int block){
                    return
                    new Comparator<Integer[]>(){
                        @Override
                        public int compare(Integer a[],Integer b[]){
                            int a1=a[0]/block;
                            int b1=b[0]/block;
                            if(a1==b1){
                                if((a1&1)==1)
                                return a[1].compareTo(b[1]);
                                else{
                                    return b[1].compareTo(a[1]);
                                }
                            }
                            return a1-b1;
                        }
                    };
                }
            
                public static Comparator<Long[]> column(int i){
                    return 
                    new Comparator<Long[]>() {
                        @Override
                        public int compare(Long[] o1, Long[] o2) {
                            return o1[i].compareTo(o2[i]);//for ascending
                            //return o2[i].compareTo(o1[i]);//for descending
                        }
                    };
                }
                public static Comparator<Integer[]> column(){
                    return 
                    new Comparator<Integer[]>() {
                        @Override
                        public int compare(Integer[] o1, Integer[] o2) {
                            //return o1[i].compareTo(o2[i]);//for ascending
                            //return o2[i].compareTo(o1[i]);//for descending
                            long a1=o1[0];
                            long a2=o2[1];
                            long b1=o2[0];
                            long b2=o1[1];
                            int ans=0;
                            if(a1*a2>b1*b2){
                                ans=1;
                            }
                            else ans=-1;
                            return ans;
                        }
                    };
                }
                public static Comparator<Integer[]> col(int i){
                    return 
                    new Comparator<Integer[]>() {
                        @Override
                        public int compare(Integer[] o1, Integer[] o2) {
                            if(o1[i]-o2[i]!=0)
                            return o1[i].compareTo(o2[i]);//for ascending
                            return o1[i+1].compareTo(o2[i+1]);
                            //return o2[i].compareTo(o1[i]);//for descending
                        }
                    };
                }
                public static Comparator<Integer> des(){
                    return 
                    new Comparator<Integer>() {
                        @Override
                        public int compare(Integer o1, Integer o2) {
                            //return o1[i].compareTo(o2[i]);//for ascending
                            return o2.compareTo(o1);//for descending
                        }
                    };
                }
                
                
                
                
                public static String reverseString(String s){
                    StringBuilder input1 = new StringBuilder(); 
                    input1.append(s);  
                    input1 = input1.reverse();
                    return input1.toString();
                }
                public static int[] scanArray(int n){
                    int a[]=new int [n];
                    //Random x=new Random();
                    for(int i=0;i<n;i++){
                        a[i]=sc.nextInt();
                    }
                    
            
                    return a;
                }
                public static long[] scanLongArray(int n){
                    long a[]=new long [n];
                    for(int i=0;i<n;i++)
                    a[i]=sc.nextLong();
            
                    return a;
                }
                public static String [] scanStrings(int n){
                    String a[]=new String [n];
                    for(int i=0;i<n;i++)
                    a[i]=sc.nextLine();
            
                    return a;
                }
                public static class InputReader {
            
                    private final InputStream stream;
                    private final byte[] buf = new byte[8192];
                    private int curChar, snumChars;
                    private SpaceCharFilter filter;
            
                    public InputReader(InputStream stream) {
                        this.stream = stream;
                    }
            
                    public int snext() {
                        if (snumChars == -1)
                            throw new InputMismatchException();
                        if (curChar >= snumChars) {
                            curChar = 0;
                            try {
                                snumChars = stream.read(buf);
                            } catch (IOException e) {
                                throw new InputMismatchException();
                            }
                            if (snumChars <= 0)
                                return -1;
                        }
                        return buf[curChar++];
                    }
            
                    public int nextInt() {
                        int c = snext();
                        while (isSpaceChar(c)) {
                            c = snext();
                        }
                        int sgn = 1;
                        if (c == '-') {
                            sgn = -1;
                            c = snext();
                        }
                        int res = 0;
                        do {
                            if (c < '0' || c > '9')
                                throw new InputMismatchException();
                            res *= 10;
                            res += c - '0';
                            c = snext();
                        } while (!isSpaceChar(c));
                        return res * sgn;
                    }
            
                    public long nextLong() {
                        int c = snext();
                        while (isSpaceChar(c)) {
                            c = snext();
                        }
                        int sgn = 1;
                        if (c == '-') {
                            sgn = -1;
                            c = snext();
                        }
                        long res = 0;
                        do {
                            if (c < '0' || c > '9')
                                throw new InputMismatchException();
                            res *= 10;
                            res += c - '0';
                            c = snext();
                        } while (!isSpaceChar(c));
                        return res * sgn;
                    }
            
                    public int[] nextIntArray(int n) {
                        int a[] = new int[n];
                        for (int i = 0; i < n; i++) {
                            a[i] = nextInt();
                        }
                        return a;
                    }
            
                    public String readString() {
                        int c = snext();
                        while (isSpaceChar(c)) {
                            c = snext();
                        }
                        StringBuilder res = new StringBuilder();
                        do {
                            res.appendCodePoint(c);
                            c = snext();
                        } while (!isSpaceChar(c));
                        return res.toString();
                    }
            
                    public String nextLine() {
                        int c = snext();
                        while (isSpaceChar(c))
                            c = snext();
                        StringBuilder res = new StringBuilder();
                        do {
                            res.appendCodePoint(c);
                            c = snext();
                        } while (!isEndOfLine(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;
                    }
            
                    private boolean isEndOfLine(int c) {
                        return c == '\n' || c == '\r' || c == -1;
                    }
            
                    public interface SpaceCharFilter {
                        public boolean isSpaceChar(int ch);
                    }
                }
                
            }
            
            class SparseTable{
                int p[][];
                int log[];
                SparseTable(int a[]){
                    log=new int[a.length];
                    for(int i=2;i<a.length;i++){
                        log[i]=log[i/2]+1;
                    }
                    p=new int[a.length][25];
                    
                    for(int i=0;i<a.length;i++){
                        p[i][0]=a[i];
                    }
                    
                    build(p);
                    //System.out.println(Arrays.toString(log));
                }
                void build(int p[][]){
                    for(int h=1;h<25;h++){
                        for(int i=0;i+(1<<(h-1))<p.length;i++){
                            p[i][h]=compare(p[i][h-1], p[i+(1<<(h-1))][h-1]);
                        }
                    }
                }
                int getO1(int l,int r){
                    int k=log[r-l+1];
                    
                        return compare(p[l][k],p[r-(1<<k)+1][k]);
                    
                }
                int compare(int a,int b){
                    return Math.max(a, b);
                }
            }
            class Pair{
                int v,w;
                Pair(int node,int weight){
                    v=node;
                    w=weight;
                }
            }
            
            