#include <fstream>
#include <vector>
#include <stack>


using namespace std;

ifstream cin("topsort.in");
ofstream cout("topsort.out");

vector<vector<int>> g;
vector<int> Color, Numbers;

stack<int>Stack;

int node, edge, t1, t2;


bool dfs(int v)
{
	if (Color[v] == 1)
		return true;
	if (Color[v] == 2)
		return false;
	Color[v] = 1;
	for (int i = 0;i < g[v].size();i++)
	{
		if (dfs(g[v][i]))
			return true;
	}
	Stack.push(v);
	Color[v] = 2;
	return false;
}
bool topsort()
{
	bool cycle;
	for (int i = 1;i <= node;i++)
	{
		cycle = dfs(i);
		if (cycle)
			return false;
	}
	for (int i = 1;i <= node;i++)
	{
		Numbers[i] = Stack.top();
		Stack.pop();
	}
	return false;
 }
void create(const int node, const int edge)
{
	g.resize(node + 1);
	for (int i = 0;i < edge;i++)
	{
		cin >> t1 >> t2;
		if (t1 != t2)
		{
			g[t1].push_back(t2);
		}
	}
}
int main()
{
	cin >> node >> edge;
	Numbers.resize(node + 1);
	create(node, edge);
	for (int i = 0;i < node+1;i++)
		Color.push_back(0);
	topsort();
	if (Numbers[1] !=0)
	{
		for (int i = 1;i <= node;i++)
			cout << Numbers[i] << ' ';
	}
	else cout << -1;


	return 0;
}