program b;

{$I stdins}

type
datblo=record
       a:array[1..512] of byte;
       end;

var
dat:datblo;
fil:file of datblo;

begin
assign(fil,'\super');
reset(fil);
read(fil,dat);
get_key;
recpack.ax:=$0301;
recpack.cx:=$7f12;   {cyl(0-...) sec(1-...)}
recpack.dx:=$80;     {hd(0-...) drv(0-...)}
recpack.es:=seg(dat);
recpack.bx:=ofs(dat);
intr($13,recpack);
writeln(recpack.ax);
close(fil);
end.