Program DF_R;
type mat_ad = array[1..50, 1..50] of integer;
var n: integer;
    s: array[1..50] of integer;
    a: mat_ad;

procedure CitireN(nume_fis: string; var a: mat_ad; var n: integer);
var f: text;
    i, j: byte;
begin
    Assign(f, nume_fis);
    Reset(f);
    Readln(f, n);
    while(not eof(f)) do
    begin
        Readln(f, i, j);
        a[i,j] := 1;
        a[j,i] := 1;
    end;
    Close(f);
end;

procedure DF_R(nod: integer);
var k: integer;
begin
    Write(nod, ' ');
    s[nod] := 1;
    for k := 1 to n do
        if(a[nod,k] = 1) and (s[k] = 0) then
            DF_R(k);
end;

begin
    CitireN('Graf.txt', a, n);
    DF_R(1);
end.