Pascal'da 30 dakika devam eden program

uses crt;
var a,b,c,d : numerator;
begin
numerator:=-9999;
repeat
for a:=-9999 to 9999 do begin
for b:=-9999 to 9999 do begin
for c:=-9999 to 9999 do begin
for d:=-9999 to 9999 do ch:=readkey;
end;
end;
end;
inc(numerator);
until numerator=9999