C++ Simple 3-Line Solution
\nclass Solution {\npublic:\n    int smallestEqual(vector<int>& nums) {\n        int i = 0;\n        while (i < nums.size() && i % 10 != nums[i]) i++;\n        
```\nclass Solution {\npublic:\n    int smallestEqual(vector<int>& nums) {\n        int i = 0;\n        while (i < nums.size() && i % 10 != nums[i]) i++;\n        return i >= nums.size() ? -1 : i;\n    }\n};\n```\n**Like it? please upvote!**
['C']