/*

                                  In the name of Allah, Most Gracious, Most Merciful


*/
#include<bits/stdc++.h>
#include<numeric>
using namespace std;

//*** constant value ***
const long double PI = 3.141592653589793238;
const double EPS = 1e-6 ;
//*** constant value ***

//****** define ********
#define IOS ios::sync_with_stdio(0); cin.tie(0); cout.tie(0);
#define ll long long
#define dd double
#define vll vector<ll>
#define vs vector<string>
#define fn(i,n) for(ll i = 0; i<n; i++)
#define f(i,a,b) for(i=a;i<b;i++)
#define f1(i,a,b) for(i=b-1;i>=a;i--)
#define pii pair<int,int>
#define pll pair<ll,ll>
#define pls pair<ll,string>
#define vpl vector<pll>
#define pb push_back
#define mk make_pair
#define x first
#define y second
#define tt cout<<"Came here"<<endl;
//****** define ********
void solve()
{
  ll vertex,edge,a,b;
  cin>>vertex>>edge;
  vector<vector<ll> >v(vertex+1);
  vector<ll>visited(vertex+1,0);
  fn(i,edge)
  {
         cin>>a>>b;
         v[a].pb(b);
         v[b].pb(a);
  }

  stack<ll>q;
  q.push(a);

  while(!q.empty())
  {
      ll s = q.top();
      q.pop();
      fn(i,v[s].size())
         if(!visited[v[s][i]])
                q.push(v[s][i]), vertex--;

    visited[s] = 1;
  }


  cout<<vertex<<endl;

}

int main()
{
    IOS;
    ll tc;
    cin>>tc;
    while(tc--)
    {
        solve();
    }


return 0;
}