class Solution {
public:
    int numRabbits(vector<int>& answers) {
        int len = answers.size(), res = 0;
        unordered_map<int, int> map;
        for (int& count : answers)++map[count];
        for (auto& p : map)
        {
            int minNum = p.first + 1;
            while (p.second > 0)
            {
                res += minNum;
                p.second -= minNum;
            }
        }
        return res;
    }
};