8_6

#pragma GCC optimize("Ofast")
#include <iostream>
#include <map>
#include <vector>
#include <deque>
#include <algorithm>
#include <bitset>
#include <cstring>
#include <math.h>
#include <string>
#include <set>
#include <iomanip>
#include <bitset>
#include <random>
#include <complex>
#include <random>
#include <cassert>
#include <unordered_map>
#include <unordered_set>
using namespace std;
#define pb push_back
#define ll long long
#define mp make_pair
#define fdeg firdeg
#define snd second
#define ins insert
#define ld long double
#define mt make_tuple
#define fst first
const double PI = acos(-1);
// = 5e5 + 17;
ll MOD = 1e9 + 7;
const int INF = 1e9;
const int MaXN = 105;
const int N = 1e6 + 1000;
const int maxlog = 18;
ld ecr = 1e-8;
vector<int> g[N];
vector<int> topsort;
bool used[N];
int cl[N];
int start , c_end;
bool has_cycle (int u)
{
    cl[u] = 1;
    for (auto v: g[u])
    {
        if (!cl[v])
        {
            if (has_cycle(v))
            {
                return true;
            }
        }
        else if (cl[v] == 1)
        {
            start = u;
            c_end = v;
            return true;
        }
    }
    cl[u] = 2;
    return false;
}

void dfs(int u)
{
    used[u] = 1;
    for(auto v : g[u])
    {
		if(!used[v]) dfs(v);
    }
    topsort.pb(u);
}
signed main()
{
    ios_base::sync_with_stdio(0);
    cin.tie(0);
    cout.tie(0);
    int n , m;
    cin >> n >> m;
    start = INF;
    for(int i = 0; i < m; i++)
    {
        int u , v;
        cin >> u >> v;
        u--, v--;
        g[u].pb(v);
    }
    for (int i = 0; i < n; i++)
    {
        if (has_cycle(i))
        {
            break;
        }
    }
    if(start < INF)
    {
        cout << -1 << "\n";
        return 0;
    }
    for(int i = 0; i < n; i++)
    {
        if(!used[i])
        {
            dfs(i);
        }
    }
    reverse(topsort.begin(), topsort.end());
    for(auto u : topsort)
    {
        cout << u + 1 << " ";
    }
    return 0;
}