#include <bits/stdc++.h>

using namespace std;
ifstream fin("sortaret.in");
ofstream fout("sortaret.out");

const int NMAX = 50005;
vector <int> graph[NMAX];
vector <int> topo;
bitset <NMAX> seen;
int n, m;
void dfs(int node)
{
    seen[node] = 1;
    for(auto& x : graph[node])
        if(seen[x] == 0)
            dfs(x);
    topo.push_back(node);
}
int main()
{
    int i, j, x, y;
    fin >> n >> m;
    for(i = 1;i <= m;i++)
    {
        fin >> x >> y;
        graph[x].push_back(y);
    }
    cout << "*";
    for(i = 1;i <= n;i++)
        if(seen[i] == 0)
            dfs(i);
    cout << "*";
    reverse(topo.begin(), topo.end());
    cout << topo.size();
    for(auto& i : topo)
        fout << i << " ";
    return 0;
}