class Solution {
public:
    int maxProduct(vector<string>& words) {
        unordered_map<int,int> masks;
        int n = words.size();

        for(int i=0;i<n;i++)
        {
            int x = 0;
            for(auto& ch : words[i])
            {
                x |= (1U<<(ch - 'a'));
            }
            masks[x] = max(masks[x],(int)words[i].size());
        }

        int sum = 0;
        for(auto& [masks1,len1] : masks)
        {
            for(auto& [masks2,len2] : masks)
            {
                if((masks1 & masks2) == 0)
                {
                    sum = max(sum,len1 * len2);
                }
            }
        }

        return sum;
    }
};