#include <iostream>
#include <fstream>
#include <vector>
#include <unordered_map>

using namespace std;


int n, m;

vector<int> sorted, visited;
unordered_map<int, vector<int>> v;

void dfs(int node) {
	if (visited[node] == 2) {
		return;
	}

	if (visited[node] == 1) {
		exit(-1);
	}

	visited[node] = 1;

	for (const auto& c : v[node]) {
		dfs(c);
	}

	visited[node] = 2;
	sorted.push_back(node);
}

int main() {
	ifstream in("sortaret.in");
	ofstream out("sortaret.out");

	in >> n >> m;
	visited = vector<int>(n+1);

	int a, b;
	for (int i = 0; i < n; ++i) {
		in >> a >> b;
		v[a].push_back(b);
	}

	for (int i = 1; i <= n; ++i) {
		if (visited[i] == 0) {
			dfs(i);
		}
	}

	for (int i = n - 1; i >= 1; --i) {
		out << sorted[i] << " ";
	}
}