#include <bits/stdc++.h>
#define int long long

using namespace std;

void solve () {
	int n, m;
	cin >> n >> m;
	
    vector <vector <int>> e (n);
    for (int i = 0; i < m; i ++) {
        int x, y;
        cin >> x >> y;
        x --; y --;

        if (x == y) {
            continue;
        }
        if (x > y) {
            swap (x, y);
        }
        e[x].push_back (y);
    }

    for (int i = 0; i < n; i ++) {
        sort (e[i].begin (), e[i].end ());
        e[i].erase (unique (e[i].begin (), e[i].end ()), e[i].end ());
    }

    int nfa = -1;
    vector <int> fa (n, -1);
    int ans = 0;
    int now;

    auto dfs = [&](auto &&self, int x) -> void {
        now = x;
        for (auto y : e[x]) {
            fa[y] = x;            
        }
        const int N = e[x].size ();
        for (int i = 0; i < N; i ++) {
            int y = e[x][i];
            if (y <= now) {
                continue;
            }
            if (i < N - 1) {
                nfa = x;
            }
            if (y == now + 1) {
                self (self, y);
            }
            nfa = x;
            while (y > now + 1) {
                ans ++;
                self (self, now + 1);
            }
        }
        if (x == n - 1) {
            return;
        }
        if (now == x) {
            if (fa[x + 1] == -1 || nfa != fa[x + 1]) {
                ans ++;
            }
            self (self, x + 1);
        }
    };
    dfs (dfs, 0);

    cout << ans << '\n';
}

signed main () {
    ios::sync_with_stdio (false);
    cin.tie (nullptr);

    int T = 1;
    cin >> T;

    while (T --) {
        solve ();
    }

    return 0;
}