Task: NL2SQL (source dataset: Spider)

Natural language to SQL, also known as NL2SQL, is the problem of generating a SQL query that can be executed on a input table, for a given natural language question.

You will be given an input table called "table" in the markdown format, as well as a question. Your task is to generate an SQL query that can be executed on the input table to answer the question.

Please ensure that the generated SQL only return relevant columns being specifically asked in the question (e.g., in SQL please don't return more than one columns in SELECT if only one column is needed to answer the given question, and similarly please refrain from using SELECT * unless the entire row is needed to answer the question).
 
When generating SQL code, please use the SQLite syntax to ensure that your SQL is executable on SQLite3. Use only columns that are present in the table, always use quotes around your column and table names (some column names have punctuation or special characters), and refer to the columns using the column-names exactly as they appear in the table, do not add or remove punctuation (underscore, slash, etc.)

No explanation, return the code only with the following markdown codeblock format : ```sql<SQL CODE>```. For example, ```sql
SELECT * FROM "table"
``` is a valid format.

Database:
region_building

Tables:

Table: building
|   Building_ID |   Region_ID | Name                      | Address                |   Number_of_Stories |   Completed_Year |
|--------------:|------------:|:--------------------------|:-----------------------|--------------------:|-----------------:|
|             1 |           1 | La Renaissance Apartments | 424 Spadina Crescent E |                  24 |             1983 |
|             2 |           2 | Hallmark Place            | 311 6th Ave N          |                  27 |             1984 |
|             3 |           4 | Saskatoon Square          | 410 22nd St E          |                  17 |             1979 |
|             4 |           5 | The Terrace Apartments    | 315 5th Ave N          |                  22 |             1980 |
|             5 |           6 | Radisson Hotel            | 405 20th St E          |                  12 |             1983 |
|             6 |           8 | The View on Fifth         | 320 5th Ave N          |                  22 |             1968 |
|             7 |           9 | The Luther                | 1223 Temperance St     |                   9 |             1978 |
|             8 |          10 | Marquis Towers            | 241 5th Ave N          |                  36 |             1966 |


Table: region
|   Region_ID | Name                  | Capital   |   Area |   Population |
|------------:|:----------------------|:----------|-------:|-------------:|
|           1 | Abruzzo               | L'Aquila  |  10763 |      1342177 |
|           2 | Aosta Valley          | Aosta     |   3263 |       128129 |
|           3 | Apulia                | Bari      |  19358 |      4090577 |
|           4 | Basilicata            | Potenza   |   9995 |       587680 |
|           5 | Calabria              | Catanzaro |  15080 |      2011537 |
|           6 | Campania              | Naples    |  13590 |      5833131 |
|           7 | Emilia-Romagna        | Bologna   |  22446 |      4429766 |
|           8 | Friuli-Venezia Giulia | Trieste   |   7858 |      1235761 |
|           9 | Lazio                 | Rome      |  17236 |      5724365 |
|          10 | Liguria               | Genoa     |   5422 |      1616993 |


Question: In which years did both buildings with more than 20 stories and buildings with less than 15 stories were completed?

db_id: region_building
tables: name: building
data: building.csv
name: region
data: region.csv
label: SELECT Completed_Year FROM building WHERE Number_of_Stories  >  20 INTERSECT SELECT Completed_Year FROM building WHERE Number_of_Stories  <  15
sqlite_path: $MMTU_HOME/data_sqlite/spider/spider_data/test_database/region_building/region_building.sqlite