program z4;
  uses crt;
 type mn=set of 'a'..'z';
 var
   mn1:mn;
   b,d:char;
   s:string;
   n,m,i,j:integer;
begin
   clrscr;
   mn1:=[];
   n:=0;
   write('vvedite text ');
   readln(s);
 for i:=1 to length(s) do
   begin
    b:=s[i];
    mn1:=mn1+[b];
   end;
 for d:='a' to 'z' do
    if (not(d in mn1))
    then begin
        write (d:3);
        n:=n+1;
    end;
 if n=0 then writeln('est vse bukvi');
 readln;
end.