Please read the following table in Markdown format and then answer the question according to the table. Table cells in one row are seperated by '|', and different rows are seperated by '
'.

Table:
| Original work | Liszt work | Forces | Date | S no. | Notes |
| --- | --- | --- | --- | --- | --- |
| Opera Lucrezia Borgia (1833) | Reminiscences de Lucrezia Borgia | piano | 1840 | S.400 | The sections are: (1) Trio du second acte and (2) Fantaisie sur des motifs favoris de l'opéra: Chanson à boire (Orgie), Duo and Finale |
| Opera Lucia di Lammermoor (1835) | Reminiscences de Lucia di Lammermoor | piano | 1835‑36 | S.397 | Based on the Sextet |
| Opera Lucia di Lammermoor (1835) | Marche et cavatine de Lucie de Lammermoor | piano | 1835‑36 | S.398 | Intended as part of the Reminiscences (S.397) but separated by the publisher |
| Lucia di Lammermoor | Valse à capriccio sur deux motifs de Lucia et Parisina | piano | 1842 | S.401 | Combines motifs from Lucia di Lammermoor and Parisina. The Valse à capriccio, S.401 was revised as No. 3 of 3 Caprices-Valses, S.214 (1850–52). |
| Opera Parisina (1833) | Valse à capriccio sur deux motifs de Lucia et Parisina | piano | 1842 | S.401 | Combines motifs from Lucia di Lammermoor and Parisina. The Valse à capriccio, S.401 was revised as No. 3 of 3 Caprices-Valses, S.214 (1850–52). |
| Nuits d'été à Pausilippe, 12 ariettas and nocturnes (voices and chamber ensemble; 1836):\n\nNo. 1, "Barcajuolo"\nNo. 9, "L'Alito di Bice"\nNo. 4, "La Torre di Biasone" | Nuits d'été à Pausilippe | piano | 1838 | S.399 |  |
| Opera La favorite (1840):\n\nDuettino (Act IV) | Spirito gentil | piano | 1847 | S.400a | Possibly same as S.742. |
| Opera Dom Sébastien (1843):\n\nFuneral march | Marche funèbre de Dom Sébastien | piano | 1844 | S.402 |  |
| Act IV | Paraphrase | piano | ? | S.744 | Lost; this was based on Theodor Kullak's transcription (paraphrase), Op. 31, which was itself dedicated to Liszt. |
| "Duettino" | Transcription | piano | ? | S.742 | Lost. Possibly same as S.400a. |
Question:
name an opera that does not have a known date.
Answer:
Duettino