Program Semen Semenich;
var c:string;
    i,g,j,k:integer;
Begin
writeln('Vvedite stroku s tochkoy na konce');
readln(c);
g:=Length(c);
if c[g]<>'.' then write('V konce net tochki')
Else
Begin
writeln('Bukvi vstrech 1 raz v stroke');
For i:=1 to g do
Begin
 k:=0;
  For j:=1 to g do
   If (c[i]=c[j]) and (c[i]<>'.') then k:=k+1;
 If k=1 then write(c[i]);
End;
End;
readln;
end.