Code:

var

i: integer

s: string;

begin

s := '$' + ThatHexString;

i := StrToInt(a);

end;

Code:

const HEX: array['A'..'F'] of INTEGER = (10, 11, 12, 13, 14, 15);

var str: string;

   Int, i: integer;

begin

READLN(str);

Int := 0;

for i := 1 to Length(str) do

   if str[i] < 'A' then

     Int := Int * 16 + ORD(str[i]) - 48

   else

     Int := Int * 16 + HEX[str[i]];

WRITELN(Int);

READLN;

end.