program deleterr;
uses crt;
var
str: String;
procedure deleter(var str: String);
var
i,a,b: Integer;
begin
for b:=1 to 2 do
 begin
  for a:=1 to length(str) do
   begin
    for i:=1 to length(str) do
     begin
      if (a<>i) and (str=str) then
       delete (str,a,1);
      end;
    end;
   end;
  end;
begin
writeln('enter word:');
readln(str);
deleter(str);
writeln(str);
readln;
end.

void foo(char *str)
{
int idx[256]
int i,read,write;
for (i=0;i<256;++i) idx[i]=0;
read=write=0;
while (str[read]) {
if (!idx[str[read]])  {
idx[str[read]]=1;
str[write++]=str[read];
}
read++;
}
str[write]=0;
}