program sortaret;
type matt = array [1..50,1..50] of 0..1;
     vect = array [1..5000] of integer;
var A : matt;
    C,Viz : vect;
    n,i,x,y,U,P : word;
    m,j : 1..100000;
    f : text;
procedure df(x:integer);
var l : integer;
begin
viz[x] := 1;
write(f,x,' ');
for l := 1 to n do
if A[x,l]=1 then if viz[l]<>1 then df(l);
end;

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);
df(1);
close(f);
end.