user
Instruction
Answer the question based on the provided table.


Table
Table Title: 'L' regarding 'List of Berlin U-Bahn stations'
Table Content:
| Station | Line | Opened | Situation |
| --- | --- | --- | --- |
| Leinestraße | U8 | 4 August 1929 | underground |
| Leopoldplatz | U6 | 8 March 1923 | underground |
| Leopoldplatz | U9 | 28 August 1961 | underground |
| Lichtenberg | U5 | 21 December 1930 | underground |
| Lindauer Allee | U8 | 24 September 1994 | underground |
| Lipschitzallee | U7 | 2 January 1970 | underground |
| Louis-Lewin-Straße | U5 | 1 July 1989 | at grade |


Question
Which subway lines are interchangeable at Leopoldplatz station?


Answer Format
The final answer should be a sentence and use the following format:
```json
{
    "answer": "your_generated_sentence_here"
}
```
rule
["Leopoldplatz is a Berlin U-Bahn station which serves as an interchange between the lines U6 and U9."]