5位字母排列组合：第一位是h或b，第四位是d，其他是u、o、a、c和n

根据给定的条件，可以得到以下所有可能的五位排列组合：\n\n1. hodun\n2. hudon\n3. haudon\n4. hcudon\n5. handuo\n6. hocdun\n7. hucdon\n8. huadon\n9. hucond\n10. hnaduo\n11. hnacuo\n12. hnacdo\n13. hoduan\n14. hudano\n15. huando\n16. hurdan\n17. hurdon\n18. hundao\n19. huncdo\n20. handuo\n21. hancuo\n22. hancdo\n23. hoadun\n24. hoduan\n25. hodnau\n26. hudnao\n27. huadon\n28. huadno\n29. huacno\n30. huacdo\n31. hnadou\n32. hnacou\n33. hnacdo\n34. hnouda\n35. hnouad\n36. hnouda\n37. hnocua\n38. hnocda\n39. hocdun\n40. hocdan\n41. hocnda\n42. hodcun\n43. hodcan\n44. hodcna\n45. hucond\n46. hucnod\n47. hucndo\n48. hucond\n49. huncdo\n50. huncod\n51. hnaduo\n52. hnacuo\n53. hnacdo\n54. hnaudo\n55. hnauod\n56. hnaudo\n57. hnouad\n58. hnouda\n59. hnouad\n60. hnocua\n61. hnocda\n62. hnucod\n63. hnocud\n64. hnocdu\n65. hnocud\n66. hocdun\n67. hocdan\n68. hocnda\n69. hodcun\n70. hodcan\n71. hodcna\n72. hnouda\n73. hnouad\n74. hnocua\n75. hnocda\n76. hnucod\n77. hnocud\n78. hnocdu\n79. hnocud\n\n总共有79种不同的五位排列组合。