#include<bits/stdc++.h>
using namespace std;
vector<int>graph[1001];
int visit[1001];
int n, e;
 
void DFS(int start)
{
    //Initial Step
    visit[start] = 1;
    cout<<start<<" ";
    stack<int>stk;
    stk.push(start);
 
    //Repeating Step
    while(!stk.empty())
    {
        int x = stk.top();
        for(int j = 0; j < graph[x].size(); j++)
        {
            int node = graph[x][j];
            if(visit[node] == 0)
            {
                visit[node] = 1;
                cout<<node<<" ";
                stk.push(node);
                x = stk.top();
                j = 0;
            }
        }
        stk.pop();
    }
}
 
int main()
{
    cin>>n>>e;
    int u, v;
    for(int i = 1; i <= e; i++)
    {
        cin>>u>>v;
        graph[u].push_back(v);
        graph[v].push_back(u);
    }
    DFS(1);
}
 

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