#include <bits/stdc++.h>
using namespace std;
void dfs(long long v, vector<long long>* gr, vector<bool>& used, vector<long long>& an)
{
    used[v] = true;
    for (long long i = 0; i < gr[v].size(); i++)
    {
        long long flag = gr[v][i];
        if (!used[flag])
            dfs(flag, gr, used, an);
    }
    an.push_back(v + 1);
}
void topSort(long long n, vector<long long>* gr, vector<bool>& used, vector<long long>& an)
{
    for (long long i = 0; i < n; i++)
        used[i] = false;
    for (long long i = 0; i < n; i++)
        if (!used[i])
            dfs(i, gr, used, an);
    reverse(an.begin(), an.end());
}
bool checky(long long v, long long& checkys, vector<long long>* gr, vector<long long>& color)
{
    color[v] = 1;
    for (size_t i = 0; i < gr[v].size(); i++)
    {
        long long flag = gr[v][i];
        if (color[flag] == 0)
        {
            if (checky(flag, checkys, gr, color))
                return true;
        }
        else if (color[flag] == 1)
        {
            checkys = flag;
            return true;
        }
    }
    color[v] = 2;
    return false;
}
int main()
{
    long long n, m;
    cin >> n >> m;
    long long a, b;
    vector<long long> gr[n + 1];
    vector<bool> used(n);
    vector<long long> an;
    vector<long long> color(n, 0);
    long long checkys = -1;
    for (long long i = 0; i < m; i++)
    {
        cin >> a >> b;
        gr[a - 1].push_back(b - 1);
    }
    for (long long i = 0; i < n; i++)
    {
        if (checky(i, checkys, gr, color))
            break;
    }
    if (checkys != -1)
        cout << "-1";
    else
    {
        topSort(n, gr, used, an);
        for (long long i = 0; i < an.size(); i++)
        {
            cout << an[i] << " ";
        }
        cout << endl;
    }
    return 0;
}