class Solution {
public:
    int longestConsecutive(vector<int>& nums) {
        unordered_set<int> set1;
        int result = 0;

        for(int& num : nums){
            set1.insert(num);
        }

        for(int& num : nums){
            int start;
            if(set1.find(num-1) == set1.end()){
                start = num;
            }

            int distance = 0;
            while(set1.find(start) != set1.end()){
                start = start + 1;
                distance++;
            }

            result = max(result, distance);
        }

        return result;
    }
};