var
i : integer
s : string;
begin
s := '$' + ThatHexString;
i := StrToInt(a);
end;

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.