PYTHON SOLUTION
\ndef destCity(self, paths: List[List[str]]) -> str:\n        source=set()\n        dest=set()\n        for i in range(len(paths)):\n            source.add(path
```\ndef destCity(self, paths: List[List[str]]) -> str:\n        source=set()\n        dest=set()\n        for i in range(len(paths)):\n            source.add(paths[i][0])\n            dest.add(paths[i][1])\n        return "".join(dest-source)\n```
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