#include<bits/stdc++.h>
using namespace std;
constexpr int M=1e5+5;
int n,m,x,y,tp,ans,stk[M];
vector<int>g[M],adj[M];
int read(){
	int x=0;char ch=getchar();
	while (!isdigit(ch)) ch=getchar();
	while (isdigit(ch)) x=x*10+ch-48,ch=getchar();
	return x;
}
void insert(int x){
	for (auto y:adj[x])
		g[y].emplace_back(x);
	stk[++tp]=x;
}
void erase(int x){
	while (stk[tp]!=x){
		for (auto y:adj[stk[tp]])
			g[y].pop_back();
		tp--;
	}
}
void solve(){
	n=read();m=read();
	for (int i=1;i<=n;i++) g[i].clear(),adj[i].clear();
	for (int i=1;i<=m;i++){
		x=read();y=read();
		if (x>y) swap(x,y);
		adj[x].emplace_back(y);
	} tp=ans=0;insert(1);
	for (int i=2;i<=n;insert(i++))
		if (g[i].empty()) ans++;
		else erase(g[i].back());
	printf("%d\n",ans);
}
int main(){int T=read();while (T--) solve();return 0;}