#include<iostream>
#include<stdio.h>
#include<string.h>
using namespace std;
int pre[1010];
int union_find(int node)
{
    int leaf=node;
    while(node!=pre[node])node=pre[node];
    while(leaf!=node)
    {
        int t_p=pre[leaf];
        pre[leaf]=node;
        leaf=t_p;
    }
    return node;
}
int main(int argc, char *argv[])
{
    // freopen("1213.in","r",stdin);
    int T;//测试用例数量T(1<=T<=25)
    int N,M;//N indicates the number of friends, the friends are marked from 1 to N. Then M lines follow. Each line consists of two integers A and B(A!=B), that means friend A and friend B know each other.(1<=N,M<=1000)
    int a,b;
    scanf("%d",&T);
    while(T--)
    {
        scanf("%d %d",&N,&M);
        memset(pre,0,sizeof(pre));
        int total=N;
        for(int i=1;i<=N;++i)
            pre[i]=i;
        while(M--)
        {
            scanf("%d %d",&a,&b);
            int p=union_find(a);
            int q=union_find(b);
            if(p!=q){
                pre[p]=q;
                total--;
            }
        }
        printf("%d\n",total);
    }
    return 0;
}