#include <bits/stdc++.h>

using namespace std;

#define FOR(i, a, b) for(int i = (a); i < (b); i++)
#define RFOR(i, a, b) for(int i = (a) - 1; i >= (b); i--)
#define SZ(a) int(a.size())
#define ALL(a) a.begin(), a.end()
#define PB push_back
#define MP make_pair
#define F first
#define S second

typedef long long LL;
typedef vector<int> VI;
typedef pair<int, int> PII;
typedef double db;

const int N = 1 << 17;

int n, m;
VI g[N];
int ans;
int ptr;

void dfs(int v, int p)
{
	assert(v == ptr - 1);
	for (int to : g[v])
	{
		while (ptr < to)
		{
			ptr++;
			ans++;
			dfs(ptr - 1, v);
		}
		if (ptr == to)
		{
			ptr++;
			dfs(to, v);
		}
	}
	while (v == 0 && ptr < n)
	{
		ptr++;
		ans++;
		dfs(ptr - 1, v);
	}
}

void solve()
{
	cin >> n >> m;
	FOR(i, 0, m)
	{
		int u, v;
		cin >> u >> v;
		u--;
		v--;
		g[u].PB(v);
		g[v].PB(u);
	}
	ans = 0;
	ptr = 1;
	dfs(0, -1);
	cout << ans << "\n";
	FOR(i, 0, n)
		g[i].clear();
}

int main()
{
	ios::sync_with_stdio(0); 
	cin.tie(0);
	int t;
	cin >> t;
	while (t--)
		solve();
	return 0;
}