type
  TSequence = set of Byte;
  TFriends = array [1..255*256] of TSequence;

procedure Print(const s: TSequence);
var
  i: Byte;
begin
  for i := 0 to 255 do if i in s then write(i:4);
end;

procedure Fill(const fName: String; var s: TFriends; var n: Integer);
var
  f: Text;
  a, b: Byte;
begin

  assign(f, fName); reset(f);

  n := 0;

  readln(f);

  while not(eof(f)) do begin

    inc(n); s[n] := [];

    read(f, a, b); readln(f);

    include(s[n], a); include(s[n], b);

  end;

  close(f);
end;

function FindMaxSequence(const s: TFriends; const n: Integer): TSequence;
var
  i, j, count, mxCount: Integer;
  temp, max: TSequence;

begin

  max := [];
  mxCount := 0;

  for i := 1 to n - 1 do begin

    temp := s[i];
    count := 0;

    for j := i + 1 to n do
     if temp <> s[j] then
      if temp * s[j] <> [] then begin
        inc(Count); temp := temp + s[j];
      end;

    if (count > mxCount) or (mxCount = 0) then begin
      mxCount := count;
      max := temp;
    end;
  end;

  FindMaxSequence := max;
end;

var
  s: TFriends;
  n: Integer;

begin
  Fill('C:\forum.txt', s, n);
  Print(FindMaxSequence(s, n));
end.