HA32_Sort(14)

#include <iostream>
#include <vector>
#include <queue>
using namespace std;

int main() {
    ios_base::sync_with_stdio(false);
    cin.tie(NULL);

    int N, M;
    cin >> N >> M;

    vector<vector<int> > adj(N + 1);
    vector<int> in_degree(N + 1, 0);

    for (int i = 0; i < M; i++) {
        int u, v;
        cin >> u >> v;
        adj[u].push_back(v);
        in_degree[v]++;
    }

    queue<int> q;
    for (int u = 1; u <= N; u++) {
        if (in_degree[u] == 0) {
            q.push(u);
        }
    }

    vector<int> topo_order;
    while (!q.empty()) {
        int u = q.front();
        q.pop();
        topo_order.push_back(u);
        for (int v : adj[u]) {
            in_degree[v]--;
            if (in_degree[v] == 0) {
                q.push(v);
            }
        }
    }

    if (topo_order.size() == N) {
        for (int u : topo_order) {
            cout << u << ' ';
        }
        cout << endl;
    } else {
        cout << -1 << endl;
    }

    return 0;
}