You are a helpful assistant. The assistant first thinks about the reasoning process in the mind and then provides the user with the answer. The reasoning process and answer must be formatted exactly as follows:
<think>
[your reasoning process here]
</think>
<answer>
[your answer here]
</answer>
You can choose to imitate the reasoning process of relevant algorithms or explore an appropriate solution on your own. DO NOT use code, and remember to focus on the logical flow.
system
You are required to solve the Travelling Salesman Problem for an undirected flight route network. Your objective is to determine the shortest possible route that visits each of the listed airports exactly once and returns to the starting point.

**Problem to Solve**

- Airports to visit: GMA, GJA, MWX, KXU, EGS, KAW, SZB, YZS, HNA
- Travel distances (in kilometers) between each pair of airports:
GMA to YZS: 14299
GMA to KAW: 11325
GMA to MWX: 13323
GMA to SZB: 11496
GMA to HNA: 14774
GMA to EGS: 12494
GMA to GJA: 13752
GMA to KXU: 19047
GJA to YZS: 6127
GJA to KAW: 17602
GJA to MWX: 13915
GJA to SZB: 18035
GJA to HNA: 13796
GJA to EGS: 10546
GJA to KXU: 10927
MWX to YZS: 12226
MWX to KAW: 4478
MWX to SZB: 4531
MWX to HNA: 1683
MWX to EGS: 12990
MWX to KXU: 11282
KXU to YZS: 11405
KXU to KAW: 15170
KXU to SZB: 12940
KXU to HNA: 10986
KXU to EGS: 17307
EGS to YZS: 10289
EGS to KAW: 14050
EGS to SZB: 14622
EGS to HNA: 13767
KAW to YZS: 15995
KAW to SZB: 2645
KAW to HNA: 5883
SZB to YZS: 16353
SZB to HNA: 5866
YZS to HNA: 11964
Please calculate the shortest tour and format your answer as follows: [Airport A, Airport B, Airport C, ..., Airport A]
user
{"directed": false, "multigraph": false, "graph": {}, "nodes": [{"name": "GMA", "id": 0}, {"name": "GJA", "id": 1}, {"name": "MWX", "id": 2}, {"name": "KXU", "id": 3}, {"name": "EGS", "id": 4}, {"name": "KAW", "id": 5}, {"name": "SZB", "id": 6}, {"name": "YZS", "id": 7}, {"name": "HNA", "id": 8}], "links": [{"weight": 14299, "source": 0, "target": 7}, {"weight": 11325, "source": 0, "target": 5}, {"weight": 13323, "source": 0, "target": 2}, {"weight": 11496, "source": 0, "target": 6}, {"weight": 14774, "source": 0, "target": 8}, {"weight": 12494, "source": 0, "target": 4}, {"weight": 13752, "source": 0, "target": 1}, {"weight": 19047, "source": 0, "target": 3}, {"weight": 6127, "source": 1, "target": 7}, {"weight": 17602, "source": 1, "target": 5}, {"weight": 13915, "source": 1, "target": 2}, {"weight": 18035, "source": 1, "target": 6}, {"weight": 13796, "source": 1, "target": 8}, {"weight": 10546, "source": 1, "target": 4}, {"weight": 10927, "source": 1, "target": 3}, {"weight": 12226, "source": 2, "target": 7}, {"weight": 4478, "source": 2, "target": 5}, {"weight": 4531, "source": 2, "target": 6}, {"weight": 1683, "source": 2, "target": 8}, {"weight": 12990, "source": 2, "target": 4}, {"weight": 11282, "source": 2, "target": 3}, {"weight": 11405, "source": 3, "target": 7}, {"weight": 15170, "source": 3, "target": 5}, {"weight": 12940, "source": 3, "target": 6}, {"weight": 10986, "source": 3, "target": 8}, {"weight": 17307, "source": 3, "target": 4}, {"weight": 10289, "source": 4, "target": 7}, {"weight": 14050, "source": 4, "target": 5}, {"weight": 14622, "source": 4, "target": 6}, {"weight": 13767, "source": 4, "target": 8}, {"weight": 15995, "source": 5, "target": 7}, {"weight": 2645, "source": 5, "target": 6}, {"weight": 5883, "source": 5, "target": 8}, {"weight": 16353, "source": 6, "target": 7}, {"weight": 5866, "source": 6, "target": 8}, {"weight": 11964, "source": 7, "target": 8}]}
You are required to solve the Travelling Salesman Problem for an undirected flight route network. Your objective is to determine the shortest possible route that visits each of the listed airports exactly once and returns to the starting point.

**Problem to Solve**

- Airports to visit: GMA, GJA, MWX, KXU, EGS, KAW, SZB, YZS, HNA
- Travel distances (in kilometers) between each pair of airports:
GMA to YZS: 14299
GMA to KAW: 11325
GMA to MWX: 13323
GMA to SZB: 11496
GMA to HNA: 14774
GMA to EGS: 12494
GMA to GJA: 13752
GMA to KXU: 19047
GJA to YZS: 6127
GJA to KAW: 17602
GJA to MWX: 13915
GJA to SZB: 18035
GJA to HNA: 13796
GJA to EGS: 10546
GJA to KXU: 10927
MWX to YZS: 12226
MWX to KAW: 4478
MWX to SZB: 4531
MWX to HNA: 1683
MWX to EGS: 12990
MWX to KXU: 11282
KXU to YZS: 11405
KXU to KAW: 15170
KXU to SZB: 12940
KXU to HNA: 10986
KXU to EGS: 17307
EGS to YZS: 10289
EGS to KAW: 14050
EGS to SZB: 14622
EGS to HNA: 13767
KAW to YZS: 15995
KAW to SZB: 2645
KAW to HNA: 5883
SZB to YZS: 16353
SZB to HNA: 5866
YZS to HNA: 11964
Please calculate the shortest tour and format your answer as follows: [Airport A, Airport B, Airport C, ..., Airport A]
test