program sortaret;
type matt = array [1..50000,1..50000] of 0..1;
     vect = array [1..50000] of integer;
var A : matt;
    C,Viz : vect;
    n,i,x,y,U,P : word;
    m,j : 1..100000;
    f : text;
begin
assign(f,'sortaret.in');
reset(f);
readln(f,n,m);

for j := 1 to m do begin
readln(f,x,y);
A[x,y] := 1;
A[y,x] := 1;
end;

close(f);
assign(f,'sortaret.out');
rewrite(f);

U := 1;
P := 0;
write(f,'1 ');
C[U] := 1;
Viz[1] := 1;

while P<U do begin
inc(P);
for i := 1 to n do
if A[i,C[P]]=1 then
               if Viz[i]<>1 then begin
                                 viz[i] := 1;
                                 inc(U);
                                 C[U] := i;
                                 write(f,i,' ');
                                 end;
end;
close(f);
end.