#include <fstream>
#include <vector>
#include <unistd.h>
#include <ios>
#include <iostream>
#include <fstream>
#include <string>


using namespace std;

const int N_MAX = 100000;

ifstream fin("dfs.in");
ofstream fout("dfs.out");

int N, M;
vector<int> G[N_MAX + 5];
bool use[N_MAX + 5];

void Dfs(int node, int padre) {
    use[node] = true;
    for (int son : G[node])
        if (!use[son])
            Dfs(son, node);
}

int main() {
    fin >> N >> M;
    for (int i = 0; i < M; ++i) {
        int x, y;
        fin >> x >> y;
        G[x].push_back(y);
        G[y].push_back(x);
    }

    Dfs(1, 0);
    return 0;
}