Вывод символов

program Project2;
 
{$APPTYPE CONSOLE}
 
uses
  SysUtils;
 
 
var
 s,org:string;
 i:integer;
 Veroyatnost,Entropiya:real;
 
 
 
begin
  writeln('Vvedite stroku i nazhmite Enter : ');
  readln(s);
  org:='';
  for i:=1 to length(s) do
    if (pos(s[i],org)=0) then org:=org+s[i];
 
  writeln('Vsego simvolov v stroke : ', length(s));
  writeln('Kolichestvo originalnyh simvolov v stroke : ', length(org));
  writeln('Perechen originalnyh simvolov: ');
  for i:=1 to length(org) do write(org[i],' ');
readln;
writeln('Esli simovoly ravnoveroyatny: ');
Veroyatnost:=1/length(org);
writeln('Veroyatnost vseh simvolov: ',Veroyatnost:1:4);
Entropiya:=ln(length(org))/ln(2);
writeln('Entropiya sistemy: ',Entropiya:2:1);
 
writeln('Esli simovoly imeyut raznyu chastotu poyavlenia: ');
 
 
readln;
end.