#include <bits/stdc++.h>
#define pb push_back
#define pf push_front
using namespace std ;
const int NR = 50001 ;
ifstream f ( "sortaret.in" ) ;
ofstream g ( "sortaret.out" ) ;
vector < int > v [ NR ] ;
deque < int > st ;
bool viz [ NR ] ;
int sol [ NR ] , cnt , n , m ;
void dfs ( int nod )
{
    viz [ nod ] = true ;
    sol [ ++ cnt ] = nod ;
    for ( size_t i = 0 ; i < v [ nod ].size() ; ++ i )
    {
        int vecin = v [ nod ][ i ] ;
        if ( !viz [ vecin ] )
        dfs ( vecin ) ;
    }
}
void input ()
{
    f >> n >> m ;
    while ( m -- )
    {
        int x , y ; f >> x >> y ;
        v [ x ].pb ( y ) ;
        v [ y ].pb ( x ) ;
    }
}
int main ()
{
    int i ;
    input() ;
    for ( i = 1 ; i <= n ; ++ i )
        if ( !viz [ i ] )
        {
            dfs ( i ) ;
            for ( int k = 1 ; k <= cnt ; ++ k )
                st.pf ( sol [ k ] ) , cout << sol [ k ] << " " ;
            cnt = 0 ;

        }
    for ( size_t j = 0 ; j < st.size() ; ++ j ) g << st [ j ] << " " ;
}