#include<stdio.h>
#include<vector>

using namespace std;

int G, H,answer;
vector<vector<int> > adj;   // 간선들을 저장.
bool visited[1005] = { 0, };

bool needC(int root) // true면 카메라 설치해야됨, false면 불필요
{
    visited[root] = 1;
    bool check = 0;
    for (int i = 0; i < adj[root].size(); i++)
    {
        if (visited[adj[root][i]] == false){
            if (needC(adj[root][i]) == false)
                check = 1;
        }
    }
    if (check == 1 || adj[root].size()==0)
    {
        answer++;
        return true;
    }
    else return false;
}
int main()
{
    freopen("input.txt", "r", stdin);   
    int t;
    scanf("%d", &t);
    while (t--)
    {
        scanf("%d %d", &G, &H);

        adj.resize(G);
        int x, y;
        for (int i = 0; i < H; i++){
            scanf("%d %d", &x, &y);
            adj[x].push_back(y);
            adj[y].push_back(x);
        }
        for (int i = 0; i < G; i++) visited[i] = 0;
        for (int i = 0; i < G;i++) 
            if (visited[i] == 0)needC(i);
        printf("%d\n", answer);
        answer = 0;
        adj.clear();
    }
    return 0;
}