#include <iostream>
#include <fstream>
#include <vector>
#include <algorithm>

std::ifstream  fin("ciclueuler.in");
std::ofstream  fout("ciclueuler.out");

std::vector<int> output;


int matrideAdiacenta[10000][10000] = {};
int vecin;

void checkEuler(int nod, int n)
{
	for (unsigned int i = 1; i <= n; i++)
	{
		if (matrideAdiacenta[nod][i]>0)
		{
			vecin = i;
			matrideAdiacenta[nod][vecin]--;
			matrideAdiacenta[vecin][nod]--;
			checkEuler(vecin, n);
		}
	}
	output.push_back(nod);
}


int main()
{
	int n, m;
	fin >> n >> m;
	for (unsigned int i = 0; i < m; i++)
	{
		int x, y;
		fin >> x >> y;
		matrideAdiacenta[x][y]++;
		matrideAdiacenta[y][x]++;
	}
	checkEuler(1, n);
	std::reverse(output.begin(), output.end());
	output.pop_back();
	for (auto x : output)
	{
		fout << x << ' ';

	}
	return 0;
}