program povtory;
uses crt;
const
  n = 30;

var
  f, q: text;
  fl: boolean;
  i, j, value, curr: integer;

begin
  clrscr;
  randomize;
  assign(f,'fail.in'); rewrite(f);
  for i:=1 to n do
    writeln(f,random(20));

  reset(f);
  assign(q,'fail.out'); rewrite(q);

  for i := 1 to n do begin
    fl := true;
    readln(f, value);

    while not EOF(f) and fl do begin
      readln(f, curr);
      if value = curr then fl := false;
    end;
    reset(f);

    for j:=1 to i-1 do begin
      readln(f, curr);
      if fl and (value = curr) then fl := false;
    end;

    readln(f, value);
    if fl then
      writeln(q, value);
  end;
  close(f);
  close(q);
end.