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

public class Main {
    public static Read scanner = new Read(System.in);
    public static final long MOD = 998244353;
    public static final int MID = (int) (1 * 1e5 + 10);
    public static long[] arr = new long[MID];
    public static int N, M, n, m;
    public static long ans;
    public static int[] row = {1, -1, 0, 0};
    public static int[] cos = {0, 0, 1, -1};
    static PrintWriter out = new PrintWriter(new BufferedWriter(new OutputStreamWriter(System.out)));
    public static ArrayList<Integer>[] list = new ArrayList[MID];
    public static HashSet<Integer>[] sets = new HashSet[MID];
    public static boolean[] pool = new boolean[MID];
    public static int iq = 1;

    public static void solve() {
        n = scanner.nextInt();
        int m = scanner.nextInt();
        for (int i = 0; i <= n + 1; i++) {
            list[i] = new ArrayList<>();
            sets[i] = new HashSet<>();
            pool[i] = false;
        }
        for (int i = 1; i <= m; i++) {
            int a = scanner.nextInt();
            int b = scanner.nextInt();
            if (a == b) continue;
            if (a > b) {
                list[b].add(a);
                sets[b].add(a);
            } else {
                list[a].add(b);
                sets[a].add(b);
            }
        }
        list[1].add(n + 1);
        for (int i = 1; i <= n; i++) Collections.sort(list[i]);
        if (n == 1) {
            out.println(0);
            return;
        }
        iq = 1;
        ans = 0;
        dfs(1);
        out.println(Math.max(0, ans));
    }

    public static void dfs(int in) {
        if (iq > n) return;
        pool[in] = true;
        if (pool[iq]) iq++;
        for (Integer i : list[in]) {
            if (i < iq) continue;
            if (pool[i]) continue;
            if (i == iq) {
                dfs(i);
            } else {
                while (i >= iq && iq <= n) {
                    if (i == iq) {
                        dfs(iq);
                    } else {
                        ans++;
                        dfs(iq);
                    }
                }
            }
        }
    }

    public static void main(String[] args) {
        int T = scanner.nextInt();
        while (T-- != 0) {
            solve();
        }
        out.flush();
    }

    static class Read {
        BufferedReader br;
        StringTokenizer st;

        public Read(InputStream in) {
            br = new BufferedReader(new InputStreamReader(in), 16384);
            eat("");
        }

        public void eat(String s) {
            st = new StringTokenizer(s);
        }

        public String nextLine() {
            try {
                return br.readLine();
            } catch (IOException e) {
                return null;
            }
        }

        public boolean hasNext() {
            while (!st.hasMoreTokens()) {
                String s = nextLine();
                if (s == null)
                    return false;
                eat(s);
            }
            return true;
        }

        public String next() {
            hasNext();
            return st.nextToken();
        }

        public int nextInt() {
            return Integer.parseInt(next());
        }

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

        public Double nextDouble() {
            return Double.parseDouble(next());
        }

        public BigInteger nextBigInteger() {
            return new BigInteger(next());
        }

        public BigDecimal nextBigDecimal() {
            return new BigDecimal(next());
        }
    }
}

Main.java:130: error: cannot find symbol
        public BigInteger nextBigInteger() {
               ^
  symbol:   class BigInteger
  location: class Read
Main.java:134: error: cannot find symbol
        public BigDecimal nextBigDecimal() {
               ^
  symbol:   class BigDecimal
  location: class Read
Main.java:131: error: cannot find symbol
            return new BigInteger(next());
                       ^
  symbol:   class BigInteger
  location: class Read
Main.java:135: error: cannot find symbol
            return new BigDecimal(next());
                       ^
  symbol:   class BigDecimal
  location: class Read
Note: Main.java uses unchecked or unsafe operations.
Note: Recompile with -Xlint:unchecked for details.
4 errors