python3. using Counter()
\ndef mostVisited(self, n: int, rounds: List[int]) -> List[int]:\n        sectors = tuple(range(1, n + 1))\n        counter = Counter(sectors)\n        counter.
```\ndef mostVisited(self, n: int, rounds: List[int]) -> List[int]:\n        sectors = tuple(range(1, n + 1))\n        counter = Counter(sectors)\n        counter.subtract(sectors[:rounds[0] - 1])\n        counter.subtract(sectors[rounds[-1]:])\n        \n        max_val = max(counter.values())\n\n        return [k for (k, v) in sorted(counter.items()) if v == max_val]\n```
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