#include <fstream>
#include <vector>
#define MAXN 100000

int n, m, val, j;
bool cycle = false;
int clr[MAXN];
std :: vector<int> g[MAXN];
std :: vector <int> ans;

void dfs (int v)
{
    clr[v] = 1;
    for (size_t i = 0; i < g[v].size(); ++i)
    {
        int to = g[v][i];
        if (clr[to] == 0)
            dfs(to);

        else if (clr[to] == 1)
        {
            cycle = true;
            return;
        }
    }
    ans.push_back(v);
    clr[v] = 2;
}

void topological_sort()
{
    ans.clear();
    for (int i = 0; i < n; ++i)
    {
        if (clr[i] == 0)
            dfs(i);
    }
}

int main()
{
    std :: ifstream in ("topsort.in");
    std :: ofstream out("topsort.out");

    in >> n >> m;
    for (int i = 0; i < m; i++)
    {
        in >> j >> val;
        g[j - 1].push_back(val - 1);
    }

    topological_sort();
    if (cycle == true)
        out << "-1";
    else
        for (int i = ans.size() - 1; i >= 0; --i)
        out << ans[i] + 1 << " ";

    in.close();
    out.close();

    return 0;
}