Pasted

program perm;
var t: text;
    a: array [0..9] of longint;
    m, n, s: ansistring;
    i, d, len_final, i2: longint;
    top: boolean;
procedure try(k: longint);
 var i, b: longint;
 begin
  if k>len_final then begin
   while s[1]='0' do delete(s, 1, 1);
   if s=m then exit();
   writeln(t, s);
   close(t);
   halt();
  end;
  if top then b:=ord(m[k])-48 else b:=9;
  for i:=b downto 0 do begin
   if a[i]>0 then begin
    s[k]:=chr(i+48);
    dec(a[i]);
    if top then
     top:=(i=ord(m[k])-48);
    try(k+1);
    inc(a[i]);
   end;
  end;
 end;
begin
 top:=true;
 assign(t, 'PERM.INP');
 reset(t);
 readln(t, n);
 readln(t, m);
 close(t);
 for i:=1 to length(n) do begin
  inc(a[ord(n[i])-48]);
  inc(d);
 end;
 assign(t, 'PERM.OUT');
 rewrite(t);
 if length(n)>length(m) then begin
  if d-a[0]>length(m) then begin
   write(t, -1);
   close(t);
   exit();
  end;
  a[0]:=length(m)-(d-a[0]);
 end;
 if length(n)>=length(m) then begin
  len_final:=length(m);
  s:=m;
  try(1);
 end else begin
  for i:=9 downto 0 do
   for i2:=1 to a[i] do
    write(t, i);
  close(t);
  halt();
 end;
 write(t, -1);
 close(t);
end.