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: CCM, YKU, BNS, TSF, MLH, GOA, CLO, INH, SIP
- Travel distances (in kilometers) between each pair of airports:
CCM to CLO: 5273
CCM to TSF: 10365
CCM to BNS: 5467
CCM to MLH: 10223
CCM to GOA: 10072
CCM to SIP: 12423
CCM to INH: 8862
CCM to YKU: 9881
YKU to CLO: 5736
YKU to TSF: 7432
YKU to BNS: 5410
YKU to MLH: 6991
YKU to GOA: 7281
YKU to SIP: 9018
YKU to INH: 15024
BNS to CLO: 1720
BNS to TSF: 8852
BNS to MLH: 8512
BNS to GOA: 8554
BNS to SIP: 10708
BNS to INH: 13013
TSF to CLO: 9732
TSF to MLH: 1636
TSF to GOA: 1275
TSF to SIP: 2123
TSF to INH: 9193
MLH to CLO: 9313
MLH to GOA: 1318
MLH to SIP: 2890
MLH to INH: 9645
GOA to CLO: 9434
GOA to SIP: 2523
GOA to INH: 9187
CLO to SIP: 11570
CLO to INH: 12819
INH to SIP: 9157
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": "CCM", "id": 0}, {"name": "YKU", "id": 1}, {"name": "BNS", "id": 2}, {"name": "TSF", "id": 3}, {"name": "MLH", "id": 4}, {"name": "GOA", "id": 5}, {"name": "CLO", "id": 6}, {"name": "INH", "id": 7}, {"name": "SIP", "id": 8}], "links": [{"weight": 5273, "source": 0, "target": 6}, {"weight": 10365, "source": 0, "target": 3}, {"weight": 5467, "source": 0, "target": 2}, {"weight": 10223, "source": 0, "target": 4}, {"weight": 10072, "source": 0, "target": 5}, {"weight": 12423, "source": 0, "target": 8}, {"weight": 8862, "source": 0, "target": 7}, {"weight": 9881, "source": 0, "target": 1}, {"weight": 5736, "source": 1, "target": 6}, {"weight": 7432, "source": 1, "target": 3}, {"weight": 5410, "source": 1, "target": 2}, {"weight": 6991, "source": 1, "target": 4}, {"weight": 7281, "source": 1, "target": 5}, {"weight": 9018, "source": 1, "target": 8}, {"weight": 15024, "source": 1, "target": 7}, {"weight": 1720, "source": 2, "target": 6}, {"weight": 8852, "source": 2, "target": 3}, {"weight": 8512, "source": 2, "target": 4}, {"weight": 8554, "source": 2, "target": 5}, {"weight": 10708, "source": 2, "target": 8}, {"weight": 13013, "source": 2, "target": 7}, {"weight": 9732, "source": 3, "target": 6}, {"weight": 1636, "source": 3, "target": 4}, {"weight": 1275, "source": 3, "target": 5}, {"weight": 2123, "source": 3, "target": 8}, {"weight": 9193, "source": 3, "target": 7}, {"weight": 9313, "source": 4, "target": 6}, {"weight": 1318, "source": 4, "target": 5}, {"weight": 2890, "source": 4, "target": 8}, {"weight": 9645, "source": 4, "target": 7}, {"weight": 9434, "source": 5, "target": 6}, {"weight": 2523, "source": 5, "target": 8}, {"weight": 9187, "source": 5, "target": 7}, {"weight": 11570, "source": 6, "target": 8}, {"weight": 12819, "source": 6, "target": 7}, {"weight": 9157, "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: CCM, YKU, BNS, TSF, MLH, GOA, CLO, INH, SIP
- Travel distances (in kilometers) between each pair of airports:
CCM to CLO: 5273
CCM to TSF: 10365
CCM to BNS: 5467
CCM to MLH: 10223
CCM to GOA: 10072
CCM to SIP: 12423
CCM to INH: 8862
CCM to YKU: 9881
YKU to CLO: 5736
YKU to TSF: 7432
YKU to BNS: 5410
YKU to MLH: 6991
YKU to GOA: 7281
YKU to SIP: 9018
YKU to INH: 15024
BNS to CLO: 1720
BNS to TSF: 8852
BNS to MLH: 8512
BNS to GOA: 8554
BNS to SIP: 10708
BNS to INH: 13013
TSF to CLO: 9732
TSF to MLH: 1636
TSF to GOA: 1275
TSF to SIP: 2123
TSF to INH: 9193
MLH to CLO: 9313
MLH to GOA: 1318
MLH to SIP: 2890
MLH to INH: 9645
GOA to CLO: 9434
GOA to SIP: 2523
GOA to INH: 9187
CLO to SIP: 11570
CLO to INH: 12819
INH to SIP: 9157
Please calculate the shortest tour and format your answer as follows: [Airport A, Airport B, Airport C, ..., Airport A]
test