用Pascal语言编写“对于一个正整数倒序输出”该怎么编写啊

上面的inttostr函数在Pascal里不被支持

Var s:string;
i:integer;

Begin
Readln(s);

for i:=length(s) downto 1 do write(s[i]);
End.

too easy ,passed by delphi7

program Project1;

{$APPTYPE CONSOLE}

uses
SysUtils;

var
v,i: integer;
s: string;
begin
writeln('please input a integer num:');
read(v);
readln;
s:= inttostr(v);
for i:=length(s) downto 1 do
Write(s[i]);
writeln;
readln;
end.

var s,g:string;
i:integer;
begin
readln(s);
g:='';
for i:=length(s) downto 1 do g:=g+s[i];
writeln(g);
end.