class Solution {
public:
    int maxProduct(vector<string>& words) {
        int n=words.size();
        vector<int> dict(n,0);
        for(int i=0;i<n;++i){
            for(char c:words[i]){
                dict[i]|=(1<<(c-'a'));
            }
        }
        
        int maxP=0;
        for(int i=0;i<n;++i){
            for(int j=i+1;j<n;++j){
                if(!(dict[i]&dict[j])){
                    int p=words[i].length()*words[j].length();
                    maxP=max(maxP,p);
                }
            }
        }
        return maxP;
    }
};