let x = '已写'; f = '已发'

  1. 1 x f
  2. 7 x f
  3. 9 x f
  4. 13 x
  5. 14 x f
  6. 20 x f
  7. 26 x f
  8. 27 x f
  9. 28
  10. 35 x
  11. 121 x f
  12. 189 x f
一笔写于: 5/24/2020, 7:51:21 PM
a hint