You are playing a game where your character should overcome different obstacles. The current problem is to come down from a cliff. The cliff has height h, and there is a moving platform on each height x from 1 to h.

Each platform is either hidden inside the cliff or moved out. At first, there are n moved out platforms on heights p_1, p_2, ..., p_n. The platform on height h is moved out (and the character is initially standing there).

If you character is standing on some moved out platform on height x, then he can pull a special lever, which switches the state of two platforms: on height x and x - 1. In other words, the platform you are currently standing on will hide in the cliff and the platform one unit below will change it state: it will hide if it was moved out or move out if it was hidden. In the second case, you will safely land on it. Note that this is the only way to move from one platform to another.

Your character is quite fragile, so it can safely fall from the height no more than 2. In other words falling from the platform x to platform x - 2 is okay, but falling from x to x - 3 (or lower) is certain death. 

Sometimes it's not possible to come down from the cliff, but you can always buy (for donate currency) several magic crystals. Each magic crystal can be used to change the state of any single platform (except platform on height h, which is unaffected by the crystals). After being used, the crystal disappears.

What is the minimum number of magic crystal you need to buy to safely land on the 0 ground level?

Input

The first line contains one integer q (1 ≤ q ≤ 100) — the number of queries. Each query contains two lines and is independent of all other queries.

The first line of each query contains two integers h and n (1 ≤ h ≤ 10^9, 1 ≤ n ≤ min(h, 2 ⋅ 10^5)) — the height of the cliff and the number of moved out platforms.

The second line contains n integers p_1, p_2, ..., p_n (h = p_1 > p_2 > ... > p_n ≥ 1) — the corresponding moved out platforms in the descending order of their heights.

The sum of n over all queries does not exceed 2 ⋅ 10^5.

Output

For each query print one integer — the minimum number of magic crystals you have to spend to safely come down on the ground level (with height 0).

Example

Input


4
3 2
3 1
8 6
8 7 6 5 3 2
9 6
9 8 5 4 3 1
1 1
1


Output


0
1
2
0
import java.util.ArrayList;
import java.util.Arrays;
import java.util.LinkedList;
import java.util.Queue;
import java.io.BufferedReader;
import java.io.InputStreamReader;
import java.util.StringTokenizer;
import java.util.Random;
import java.io.PrintWriter;
/*
    Solution Created: 18:40:08 08/10/2019
    Custom Competitive programming helper.
*/
public class Main {
	public static void solve(Reader in, Writer out) {
		int t = in.nextInt();
		while(t-->0) {
			int h = in.nextInt();
			int n = in.nextInt();
			int[] a = new int[n+1];
			for(int i = 0; i<n; i++) a[i] = in.nextInt();
			a[n] = 0;
			int ans = 0;
			int i = 0;
			while(i<n) {
				int cur = a[i];
				int to = a[i+1];
				if(to==0) break;
				int dist =  cur-to;
				if(dist==1) {
					if(a[i+2]!=cur-2) {
						ans++;
						a[i+1] = cur-2;
						i++;
					}else {
						i+=2;
					}
				}else {
					 a[i] = a[i+1]+1;
				}
			}
			out.println(ans);
		}
	}
	
	public static void main(String[] args) {
		Reader in = new Reader();
		Writer out = new Writer();
		solve(in, out);
		out.exit();
	}

static class Graph {
	private ArrayList<Integer> con[];
	private boolean[] visited;

	public Graph(int n) {
		con = new ArrayList[n];
		for (int i = 0; i < n; ++i)
			con[i] = new ArrayList();
		visited = new boolean[n];
	}

	public void reset() {
		Arrays.fill(visited, false);
	}

	public void addEdge(int v, int w) {
		con[v].add(w);
	}

	public void dfs(int cur) {
		visited[cur] = true;
		for (Integer v : con[cur]) {
			if (!visited[v]) {
				dfs(v);
			}
		}
	}

	public void bfs(int cur) {
		Queue<Integer> q = new LinkedList<>();
		q.add(cur);
		visited[cur] = true;
		while (!q.isEmpty()) {
			cur = q.poll();
			for (Integer v : con[cur]) {
				if (!visited[v]) {
					visited[v] = true;
					q.add(v);
				}
			}
		}
	}
}

static class Reader {
	static BufferedReader br;
	static StringTokenizer st;
	private int charIdx = 0;
	private String s;

	public Reader() {
		this.br = new BufferedReader(new InputStreamReader(System.in));
	}

	public int[] na(int n) {
		int[] a = new int[n];
		for (int i = 0; i < n; i++)
			a[i] = nextInt();
		return a;
	}

	public double[] nd(int n) {
		double[] a = new double[n];
		for (int i = 0; i < n; i++)
			a[i] = nextDouble();
		return a;
	}

	public char nextChar() {
		if (s == null || charIdx >= s.length()) {
			if (st == null || !st.hasMoreTokens())
				try {
					readLine();
				} catch (Exception e) {
				}
			s = st.nextToken();
			charIdx = 0;
		}
		return s.charAt(charIdx++);
	}

	public long[] nl(int n) {
		long[] a = new long[n];
		for (int i = 0; i < n; i++)
			a[i] = nextLong();
		return a;
	}

	public char[] nca() {
		return next().toCharArray();
	}

	public String[] nS(int n) {
		String[] a = new String[n];
		for (int i = 0; i < n; i++)
			a[i] = next();
		return a;
	}

	public int nextInt() {
		if (st == null || !st.hasMoreTokens())
			try {
				readLine();
			} catch (Exception e) {
			}
		return Integer.parseInt(st.nextToken());
	}

	public double nextDouble() {
		if (st == null || !st.hasMoreTokens())
			try {
				readLine();
			} catch (Exception e) {
			}
		return Double.parseDouble(st.nextToken());
	}

	public Long nextLong() {
		if (st == null || !st.hasMoreTokens())
			try {
				readLine();
			} catch (Exception e) {
			}
		return Long.parseLong(st.nextToken());
	}

	public String next() {
		if (st == null || !st.hasMoreTokens())
			try {
				readLine();
			} catch (Exception e) {
			}
		return st.nextToken();
	}

	public static void readLine() {
		try {
			st = new StringTokenizer(br.readLine());
		} catch (Exception e) {
		}
	}
}

static class Sort {
	static Random random = new Random();
	public static void sortArray(int[] s) {
        shuffle(s);
        Arrays.sort(s);
    }
	public static void sortArray(long[] s) {
        shuffle(s);
        Arrays.sort(s);
    }
	public static void sortArray(String[] s) {
        shuffle(s);
        Arrays.sort(s);
    }
	public static void sortArray(char[] s) {
        shuffle(s);
        Arrays.sort(s);
    }
    private static void shuffle(int[] s) {
        for (int i = 0; i < s.length; ++i) {
            int j = random.nextInt(i + 1);
            int t = s[i];
            s[i] = s[j];
            s[j] = t;
        }
    }
    private static void shuffle(long[] s) {
        for (int i = 0; i < s.length; ++i) {
            int j = random.nextInt(i + 1);
            long t = s[i];
            s[i] = s[j];
            s[j] = t;
        }
    }
    private static void shuffle(String[] s) {
        for (int i = 0; i < s.length; ++i) {
            int j = random.nextInt(i + 1);
            String t = s[i];
            s[i] = s[j];
            s[j] = t;
        }
    }
    private static void shuffle(char[] s) {
        for (int i = 0; i < s.length; ++i) {
            int j = random.nextInt(i + 1);
            char t = s[i];
            s[i] = s[j];
            s[j] = t;
        }
    }
}

static class Util{
	    static boolean isPrime(int n) { 
	        if (n <= 1) return false; 
	        if (n <= 3) return true; 
	        if (n % 2 == 0 || n % 3 == 0) return false; 
	        for (int i = 5; i * i <= n; i = i + 6) 
	            if (n % i == 0 || n % (i + 2) == 0) 
	            return false; 
	        return true; 
	    }
		public static int upperBound(long[] a, long v) {
			int l=0, h=a.length-1, ans = -1;
			while(l<h) {
				int mid = (l+h)/2;
				if(a[mid]<=v) {
					ans = mid;
					l = mid+1;
				}else h = mid-1;
			}
			return ans;
		}
		public static int lowerBound(long[] a, long v) {
			int l=0, h=a.length-1, ans = -1;
			while(l<h) {
				int mid = (l+h)/2;
				if(v<=a[mid]) {
					ans = mid;
					h = mid-1;
				}else l = mid-1;
			}
			return ans;
		}
	    public static boolean[] getSieve(int n) {
	        boolean[] isPrime = new boolean[n+1];
	        for (int i = 2; i <= n; i++) isPrime[i] = true;
	        for (int i = 2; i*i <= n; i++) if (isPrime[i]) 
	                for (int j = i; i*j <= n; j++) isPrime[i*j] = false;
	        return isPrime;
	    }
	    public static int gcd(int a, int b) { 
	        if (a == 0) 
	            return b; 
	        return gcd(b%a, a); 
	    }
		public static long modAdd(long a, long b, long mod) {
			return (a%mod+b%mod)%mod;
		}
		public static long modMul(long a, long b, long mod) {
			return ((a%mod)*(b%mod))%mod;
		}
		public static void dbg(Object... o) { 
			System.out.println(Arrays.deepToString(o)); 
		}
	}

static class Writer {
	private PrintWriter pw;
	public Writer(){
		pw = new PrintWriter(System.out);
	}
	
	public void printArray(int[] a) {
		for(int i = 0; i<a.length; i++) print(a[i]+" ");
	}
	public void printlnArray(int[] a) {
		for(int i = 0; i<a.length; i++) print(a[i]+" ");
		pw.println();
	}
	public void printArray(long[] a) {
		for(int i = 0; i<a.length; i++) print(a[i]+" ");
	}
	public void printlnArray(long[] a) {
		for(int i = 0; i<a.length; i++) print(a[i]+" ");
		pw.println();
	}
	public void print(Object o) {
		pw.print(o.toString());
	}
	public void println(Object o) {
		pw.println(o.toString());
	}
	public void println() {
		pw.println();
	}
	public void flush() {
		pw.flush();
	}
	public void exit() {
		pw.close();
	}
}
}
