HDU1213
#include<iostream>
using namespace std;
const int N = 1e4+10;
int p[N];
int t;
int find(int x){
if(p[x] != x) p[x] = find(p[x]);
return p[x];
}
int main(){
cin >> t;
while(t--){
int n,m;
cin >> n >> m;
for(int i = 1; i <= n; i++) p[i] = i;
while(m--){
int a,b;
cin >> a >> b;
p[find(a)] = find(b);
}
int cnt = 0;
for(int i = 1; i <= n; i++)
if(p[i] == i) cnt++;
cout << cnt << endl;
}
return 0;
}