//#pragma comment(linker, "/STACK:16777216") //for c++ Compiler

#include <stdio.h>

#include <iostream>

#include <fstream>

#include <cstring>

#include <cmath>

#include <stack>

#include <string>

#include <map>

#include <set>

#include <list>

#include <queue>

#include <vector>

#include <algorithm>

#define Max(a,b) (((a) > (b)) ? (a) : (b))

#define Min(a,b) (((a) < (b)) ? (a) : (b))

#define Abs(x) (((x) > 0) ? (x) : (-(x)))

#define MOD 1000000007

#define pi acos(-1.0)

using namespace std;

typedef long long           ll      ;

typedef unsigned long long  ull     ;

typedef unsigned int        uint    ;

typedef unsigned char       uchar   ;

template<class T> inline void checkmin(T &a,T b){if(a>b) a=b;}

template<class T> inline void checkmax(T &a,T b){if(a<b) a=b;}

const double eps = 1e-      ;

const int N =             ;

const int M = *      ;

const ll P = 10000000097ll   ;

const int MAXN =     ;

int n;

int g[][], vis[], ans[];

void init(){

    memset(g, , sizeof(g));

}

bool dfs(int pos, int level){

    ans[level] = pos;

    if(level >= n){

        return true;

    }

    for(int i = ; i <= n; ++i){

        if(i == pos)    continue;

        if(!vis[i] && g[pos][i]){

            vis[i] = ;

            if(dfs(i, level + )){

                return true;

            }

            vis[i] = ;

        }

    }

}

int main(){

    std::ios::sync_with_stdio(false);

    int i, j, t, k, u, v, numCase = ;

    cin >> t;

    while(t--){

        init();

        cin >> n;

        for(i = ; i <= n * (n - ) / ; ++i){

            cin >> u >> v;

            g[u][v] = ;

        }

        for(i = ; i <= n; ++i){

            memset(vis, , sizeof(vis));

            memset(ans, , sizeof(ans));

            vis[i] = ;

            if(dfs(i, ))   break;

            vis[i] = ;

        }

        if(i != n + ){

            for(i = ; i < n; ++i){

                cout << ans[i] << ' ';

            }

            cout << ans[n] << endl;

        } else{

            cout << "Impossible" << endl;

        }

    }

    return ;

}