#include <bits/stdc++.h>

#define ll long long
#define el endl
#define umi unordered_map<int, int>
#define umll unordered_map<ll, ll>
#define all(vect) vect.begin(), vect.end()
#define reset(A) memset(A, 0, sizeof(A))

const int mod = 1e9 + 7;

using namespace std;

int v[1005][1005];
int n, m;
bool check[1005];
void khoitao(){
    for(int i=1;i<=n;i++) check[i]=0;
}
void dfs(int u){
    check[u] = 1;
    for(int i = 1; i <= n; i++)
        if(v[u][i] && check[i] == 0)
            dfs(i);
}

int ktcanhcau(){
    khoitao();
    dfs(1);
    for(int i=1;i<=n;i++){
        if(check[i]==0) return 1;
    }
    return 0;
}

void solve()
{
    cin >> n >> m;
    reset(v);
    int x, y;
    for(int i = 0; i < m; i++)
    {
        cin >> x >> y;
        v[x][y] = 1;
        v[y][x] = 1;
    }
    for(int i = 1; i < n; i++)
    {
        for(int j = i + 1; j <= n; j++)
        {
            if(v[i][j]==1)
            {
                v[i][j] = v[j][i] = 0;
                if(ktcanhcau()==1)
                {
                    cout << i << " " << j << " ";
                }
                v[i][j] = v[j][i] = 1;
            }

        }

    }
    cout << el;
}

int main(){
    int t ;
    cin >> t;
    while(t--)
    {
        solve();
    }
    return 0;
}