#define pb push_back
#include <vector>
#include <string>
#include <sstream>
#include <algorithm>
#include <iostream>
using namespace std;

bool visited[100005];
vector< vector<int> > g;

int dfs(int start) {
    if (!visited[start]) {
        visited[start] = 1;
        for (int i=0; i < g[start].size(); i++) {
            dfs(g[start][i]);
        }
    }
    return 0;
}


int main() {
    int x;
    cin >> x;
    for (int i=0; i < x; i++) {

        memset(visited, 0, sizeof(visited));
        int a, b;
        cin >> a >> b;
        for (int j=0; j < b; j++) {
            int u, v;
            cin >> u >> v;
            g[u].pb(v);
            g[v].pb(u);
        }

        int comp = 0;
        for (int k=0; k < a; k++) {
            if (!visited[k]) {
                comp += 1;
                dfs(k);
            }
        }

        cout << comp << endl;

    }
    system("pause");
}