program z12_10;
uses crt;
var ch,povt:set of char;
st:string;
i:integer;
BEGIN
write('st=');
readln(st);
ch:=[];
povt:=[];
for i:=1 to length(st) do
if not(st[i] in ch) then ch:=ch+[st[i]]
else povt:=povt+[st[i]];
for i:=0 to 255 do
if chr(i) in ch-povt then write(chr(i):3);
readln;
END.