program random;
  var
    a:array[1..100]of integer;
    n,m,x,i,j,k:integer;
    f1,f2:text;
  begin
    assign(f1,'random.in');reset(f1);
    assign(f2,'random.out');rewrite(f2);
    readln(f1,n);
    fillchar(a,sizeof(a),0);
    m:=1;
    read(f1,a[1]);
    for i:=2 to n do begin
      read(f1,x);
      j:=1;
      while (j<=m)and(x>a[j]) do inc(j);
      if (x<>a[j+1])and(x<>a[j]) then begin
        for k:=m+1 downto j+1 do a[k]:=a[k-1];
        a[j]:=x;
        inc(m);
      end;
    end;
    close(f1);
    writeln(f2,m);
    for i:=1 to m do write(f2,a[i],' ');
    close(f2);
  end.