Task: Schema-Matching (source dataset: HXD)

Task: 
Please identify the matching columns between Table A and Table B. For each column in Table A, specify the corresponding column in Table B. If a column in A has no corresponding column in Table B, you can map it to null. Represent each column mapping using a pair of column headers in a list, i.e., [Table A Column, Table B column or null]. Provide the mapping for each column in Table A and return all mappings in a list.

No explanation and return the matching columns in a structured JSON format: {"column_mappings": <a list of column pairs>}.

TableA:
| Country    | Food insecurity        | Affected 2017   | In Need 2017   | Targeted 2017   | % targeted   |
|:-----------|:-----------------------|:----------------|:---------------|:----------------|:-------------|
| Nigeria    | severe food unsecure   | 5118752         | 5118752        | -               | -            |
| Senegal    | food insecure          | 3988146         | 881365         | 250000          | 28           |
| Mali       | food insecure          | 3529468         | 3529468        | 700000          | 20           |
| Mali       | moderate food insecure | 3034468         | 3034468        | 205000          | 7            |
| Mali       | severe food unsecure   | 495000          | 495000         | 495000          | 100          |
| Gambia     | severe food unsecure   |                 |                |                 | -            |
| Mauritania | moderate food insecure | 859471          | -              | -               | -            |
| Niger      | food insecure          | 5118867         | 1270739        | 650000          | 51           |
| Cameroon   | food insecure          | 2819000         | 2819000        | 839260          | 30           |
| Mauritania | severe food unsecure   | 443497          | -              | -               | -            |

TableB:
| country   | region   | sector                         |   personnes_en_besoin |
|:----------|:---------|:-------------------------------|----------------------:|
| Niger     | Maradi   | Education                      |                 17402 |
| Niger     | Dosso    | Securite alimentaire           |                 99444 |
| Niger     | Dosso    | Protection                     |                     0 |
| Niger     | Tahoua   | Sante                          |                216349 |
| Niger     | Zinder   | Education                      |                 11176 |
| Niger     | Agadez   | Nutrition                      |                 42706 |
| Niger     | Niamey   | Securite alimentaire           |                 12368 |
| Niger     | Agadez   | Eau, assainissement et hygiene |                 43279 |
| Niger     | Maradi   | Nutrition                      |                452230 |
| Niger     | Diffa    | Abris urgence et NFI           |                255052 |



source_headers: Country
In Need 2017
target_headers: country
personnes_en_besoin
column_mappings: Country
country
In Need 2017
personnes_en_besoin
output: {"column_mappings": [["Country", "country"], ["Food insecurity", null], ["Affected 2017", null], ["In Need 2017", "personnes_en_besoin"], ["Targeted 2017", null], ["% targeted", null]]}