#include <iostream>
#include <vector>
#include <set>
#include <algorithm>
#include <cstdio>
#include <cstring>
using namespace std;

const long MOD = 998244353;
const int MID = 1e5 + 10;
long arr[MID];
int N, M, n, m;
long ans;
int row[] = {1, -1, 0, 0};
int cos[] = {0, 0, 1, -1};
vector<int> list[MID];
set<int> sets[MID];
bool pool[MID];
int iq = 1;

inline void fastRead(int &x) {
    x = 0;
    char ch = getchar();
    bool neg = false;
    while (ch < '0' || ch > '9') {
        if (ch == '-') neg = true;
        ch = getchar();
    }
    while (ch >= '0' && ch <= '9') {
        x = x * 10 + ch - '0';
        ch = getchar();
    }
    if (neg) x = -x;
}

void dfs(int in) {
    if (iq > n) return;
    pool[in] = true;
    if (pool[iq]) iq++;
    for (int 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);
                }
            }
        }
    }
}

void solve() {
    fastRead(n);
    fastRead(m);
    for (int i = 0; i <= n + 1; i++) {
        list[i].clear();
        sets[i].clear();
        pool[i] = false;
    }
    for (int i = 1; i <= m; i++) {
        int a, b;
        fastRead(a);
        fastRead(b);
        if (a == b) continue;
        if (a > b) {
            list[b].push_back(a);
            sets[b].insert(a);
        } else {
            list[a].push_back(b);
            sets[a].insert(b);
        }
    }
    list[1].push_back(n + 1);
    for (int i = 1; i <= n; i++) sort(list[i].begin(), list[i].end());
    if (n == 1) {
        cout << 0 << endl;
        return;
    }
    iq = 1;
    ans = 0;
    dfs(1);
    cout << max(0L, ans) << endl;
}

int main() {
    int T;
    fastRead(T);
    while (T--) {
        solve();
    }
    return 0;
}