Task: Schema-Matching (source dataset: prospect)

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:
| AgencyID   | MiddleInitial   | Employer             | LastName   | OwnOrRentFlag   | Country               | FirstName   | Gender   | AddressLine1         | AddressLine2   | PostalCode   | City           | State                | Phone          |
|:-----------|:----------------|:---------------------|:-----------|:----------------|:----------------------|:------------|:---------|:---------------------|:---------------|:-------------|:---------------|:---------------------|:---------------|
| PEL0       |                 | Bfinks               | PELiAND    | O               | Unit4dStatesofAmwrifz | Netti       | f        | 21847 olympia street |                | T6b 1i1      | Fairbanks      | MA                   | 1-712-522-6088 |
| LED1       |                 |                      | LEvUC      | U               | UnitedSta4es8fAherixa | TRUDY       | F        | 245 congress court   | APT. 624       | 77281        | Quebec         | PA                   | 1-626-426-4298 |
| lat2       |                 |                      | lztif      | O               | UniyedetatesifAmerjca | ireland     |          | 6517 frailing west   |                | 91355        | Henderson      | Alberta              | 1-524-787-8784 |
| RUD3       |                 | Ait9roductxChdmicals | RUDcICK    | O               | Csnada                | Misti       |          | 11449 blalock park   |                | 36615        | Salem          | AR                   | 1-741-997-1688 |
| JAY4       | M               | Oshkozh              | JAuAMANNE  | O               | Canadw                | sarena      | f        | 18354 dodd court     | Apt. 619       | t6a 1i3      | Toledo         | OR                   | 1-002-194-1991 |
| tod5       | Z               |                      | todo       | R               | UnitedStztes0fAmsgica | Paulette    | M        | 14117 roxboro street |                | A2b 1v3      | Corpus Christi | VA                   | 1-441-371-7651 |
| Kan6       | R               | VerazumEnergy        | Kannl      | O               | xanada                | AMALITA     | m        | 24697 FLORENCE WEST  |                | 49513        | Salt Lake City | OH                   | 1-957-940-5980 |
| Din7       | Z               | IDT                  | finkel     | U               | Un8heddtateaofAmerica | Ernesto     |          | 6488 applewood drive |                | M5d 1v6      | Brownsville    | Prince Edward Island | 1-768-633-4096 |
| Thi8       |                 | AdamsResourcrsEb4rvy | yhlbodeaux | O               | UnitedwtatrsofAkerifa | Toby        |          | 17404 gale court     |                | V6c 1q1      | Escondido      | NV                   | 1-107-689-2155 |
| May9       |                 | MGICInvestjejt       | Mayo       | O               | Uni6edctates9fwmerica | evangelia   |          | 15913 alexis street  |                | 99716        | Los Angeles    | Ontario              | 1-173-594-6096 |

TableB:
| gncd    | mddlntl   | mplr                           | lstnm                         | wnrrntflg   | cntr                     |    ncm |   nmbrcrs | nmbrchldrn   | mrtlstts   |   g |   crdtrtng | nmbrcrdtcrds   |           ntwrth |
|:--------|:----------|:-------------------------------|:------------------------------|:------------|:-------------------------|-------:|----------:|:-------------|:-----------|----:|-----------:|:---------------|-----------------:|
| Iok7501 | n         | FM Global                      | Iokwiqojocjanndatkdzgymym     | U           | United States of America |  94490 |         3 |              | U          |   7 |        580 |                | 321776           |
| tia7502 |           | MGIC Investment                | tiabxgseasiibxakctfzhfwotp    | R           | Canada                   |   7037 |         4 | 4.0          | S          |  48 |        683 | 2.0            |      2.29232e+06 |
| AOI7503 | u         | Ross Stores                    | AOIWIWTIHIXOJ                 | O           |                          | 419269 |         1 | 5.0          | M          |  14 |        411 | 2.0            | 969707           |
| PJQ7504 |           |                                | PJQSPMBUHYQKBOZ               | U           | United States of America |  76681 |         4 | 5.0          | W          |  29 |        818 | 9.0            |      3.89946e+06 |
| SDV7505 |           | Alliance One International     | SDVLJWXENNGWCQMIW             | R           | United States of America | 209116 |         2 | 4.0          | U          |  69 |        370 | 7.0            |      3.74922e+06 |
| Hga7506 | F         | Sally Beauty Holdings          | Hgakmykzeunwkiaxayulpwyxrcuev | O           |                          | 212203 |         0 | 0.0          | U          |  47 |        833 | 6.0            |      3.65853e+06 |
| Beo7507 | D         | Wisconsin Energy               | Beotomyndkiqryllkvpavllytov   | U           | Canada                   |  42018 |         5 | 5.0          | M          |   0 |        536 | 2.0            |      1.73846e+06 |
| Qum7508 |           | Carpenter Technology           | Qumxrssnd                     | R           | United States of America |  90446 |         0 | 0.0          | S          |  46 |        775 | 0.0            |      3.3073e+06  |
| Hud7509 | v         | Liberty Mutual Insurance Group | Hudlpfwjagzbnznyhamjkhbf      | R           | United States of America |  16274 |         1 | 1.0          | M          |   6 |        765 | 3.0            |      1.81642e+06 |
| jba7510 |           | Black & Decker                 | jbabemsfwdyeihxq              | O           | Canada                   |  22215 |         5 | 2.0          | M          |  22 |        555 | 6.0            |      2.59925e+06 |



source_headers: AgencyID
MiddleInitial
Employer
LastName
OwnOrRentFlag
Country
target_headers: gncd
mddlntl
mplr
lstnm
wnrrntflg
cntr
column_mappings: AgencyID
gncd
MiddleInitial
mddlntl
Employer
mplr
LastName
lstnm
OwnOrRentFlag
wnrrntflg
Country
cntr
output: {"column_mappings": [["AgencyID", "gncd"], ["MiddleInitial", "mddlntl"], ["Employer", "mplr"], ["LastName", "lstnm"], ["OwnOrRentFlag", "wnrrntflg"], ["Country", "cntr"], ["FirstName", null], ["Gender", null], ["AddressLine1", null], ["AddressLine2", null], ["PostalCode", null], ["City", null], ["State", null], ["Phone", null]]}