У меня exitcode=1 почему, где ошибка?

Program p1;
var
  a, b, c: set of byte;
  f, g: text;
  i, x: byte;
 
begin
  a := [];
  b := [];
  assign(f, 'prob1.in');
  assign(g, 'prob1.out');
  reset(f);
  rewrite(g);
  while not eof(f) do
  begin
    while not eoln(f) do
    begin
      read(f, x);
      include(a, x);
    end;
    readln(f);
    while not eoln(f) do
    begin
      read(f, x);
      include(b, x);
    end;
  end;
  close(f);
 
  writeln(g, 'Set A: ');
  i := 0;
  for x := 0 to 255 do
    if x in a then
    begin
      write(g, x:4);
      inc(i);
    end;
  writeln(g);
  writeln(g, 'Cardinal A= ', i);
  writeln(g, 'Set B: ');
  i := 0;
  for x := 0 to 255 do
    if x in b then
    begin
      write(g, x:4);
      inc(i);
    end;
  writeln(g);
  writeln(g, 'Cardinal B= ', i);
  c := [];
  c := A - B;
  writeln(g, 'Set A-B: ');
  for x := 0 to 255 do
    if x in c then
      write(g, x:4);
  writeln(g);
  c := [];
  c := A * B;
  writeln(g, 'Set A*B: ');
  for x := 0 to 255 do
    if x in c then
      write(g, x:4);
  writeln(g);
  c := [];
  c := A + B;
  writeln(g, 'Set A+B: ');
  for x := 0 to 255 do
    if x in c then
      write(g, x:4);
  writeln(g);
  c := [];
  c := B - A;
  writeln(g, 'Set B-A: ');
  for x := 0 to 255 do
    if x in c then
      write(g, x:4);
  writeln(g);
  writeln(g, 'A submultimea B? ', a <= b);
  writeln(g, 'B submultimea A? ', b <= a);
  close(g);
end.