var
  mass: array [1..1000] of integer;

  count, balbal, maxcount:integer;
  i, j, n:integer;
  kontr:integer;

begin
  Readln (n);
  for i:=1 to n do
    Readln (mass[i]);

  for i:=1 to n do
     Write (mass[i]:4);
  Writeln ();
  Writeln ('---------------------');
  for i:=1 to n do
    for j:=2 to n do
    begin
      if (mass[i] = mass[j]) then break;

      count := mass[i] + mass[j];
      if (count mod 3 = 0) then balbal := count
      else break;

      if (balbal > maxcount) then maxcount := balbal;
    end;


if (maxcount = 0) then
  begin
    Writeln ('Программа завершена. Контроль не пройден. ');
    exit;
  end;

Writeln ('Введите контрольное значение');
Readln (kontr);


if (kontr = maxcount) then
  begin
    Writeln ('Контроль пройден')
  end

  else
  begin
    Writeln ('Контроль не пройден');
  end;
end.