pascal中在不知道输入数数位时怎样编程能使输出数是倒序输出的

program test;

procedure ReversePrint();
var
   a: char;

begin
   read(a);
   if a <> '#' then
   begin
      ReversePrint();
      write(a);
   end else
   begin
      readln;
   end;
end;

begin
   ReversePrint();
   readln;
end.

program ch1;
var s,sub:string;
k:integer;
begin read(s);
for k:=2 to length(s) do
begin sub:=copy(s,k,1);
delete(s,k,1);
insert(sub,s,1);
end;
write(s);
end.

var i:integer;
st:string;
begin
readln（st);
for i:=length(st) downto 1 do
write(st[i]);
end.

j:=0;