[Python3] 1 line
\nclass Solution:\n    def smallestEqual(self, nums: List[int]) -> int:\n        return min([i for i,el in enumerate(nums) if i%10==el],default=-1)\n
```\nclass Solution:\n    def smallestEqual(self, nums: List[int]) -> int:\n        return min([i for i,el in enumerate(nums) if i%10==el],default=-1)\n```
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