#include<bits/stdc++.h>
using namespace std;
int graph[105][105]= {0},i,j,n,k,mx;
vector<int>store,res;
bool color[105];

bool isblack(int node)
{
    for(i=1; i<=node; i++)
    {
        if(graph[node][i]==1 && color[i]==true)
        {
            return false;
        }
    }
    return true;
}
void graphclr(int nodenum)
{
    if(nodenum>n)
    {
        if(mx<store.size())
        {
            mx=store.size();
            res=store;
        }
        return;
    }
    if(isblack(nodenum)==true)
    {
        color[nodenum]=true;
        store.push_back(nodenum);
        graphclr(nodenum+1);
        store.pop_back();
        color[nodenum]=false;
    }
    graphclr(nodenum+1);
}
int main()
{
    int t,x,y;
    cin>>t;
    while(t--)
    {
        memset(graph,0,sizeof(graph));
        memset(color,0,sizeof(color));
        store.clear();
        res.clear();
        cin>>n>>k;
        for(i=0; i<k; i++)
        {
            cin>>x>>y;
            graph[x][y]=1;
            graph[y][x]=1;
        }
        mx=0;
        graphclr(1);
        cout<<mx<<endl;
        for(i=0; i<mx; i++)
        {
            if(i>0)
                cout<<" ";
            cout<<res[i];
        }
        cout<<endl;
    }
    return 0;
}