#include<stdio.h>

 #include<algorithm>

 #include<iostream>

 #include<string.h>

 using namespace std;

 const int maxn=;

 int fa[maxn];

 int fin(int x)

 {

     return fa[x]==x?fa[x]:fa[x]=fin(fa[x]);

 }

 int unin(int x,int y){

 return fa[fin(y)]=fin(x);

 }

 int main()

 {

     int t,a,b;

     int m,n;

     cin>>t;

     while(t--){

      cin>>m>>n;

      for(int i=;i<=m;i++){

         fa[i]=i;

      }

      for(int i=;i<n;i++){

         scanf("%d%d",&a,&b);

         if(fin(a)!=fin(b)){

             unin(a,b);

         }

      }

      int temp=;

      for(int i=;i<=m;i++){

         if(fa[i]==i){

             temp++;

         }

      }

      cout<<temp<<endl;

 getchar();

     }

 }