static int wing=[]()

 {

     std::ios::sync_with_stdio(false);

     cin.tie(NULL);

     return ;

 }();

 class Solution

 {

 public:

     string mostCommonWord(string paragraph, vector<string>& banned)

     {

         unordered_map<string,int> simap;

         for(string s:banned)

             simap[s]=-;

         int beg=,flag=,max=;

         paragraph.push_back(' ');

         string res;

         int sz=paragraph.length();

         for(int i=;i<sz;i++)

         {

             if(isalpha(paragraph[i]))

                 paragraph[i]=tolower(paragraph[i]);

             else if(paragraph[i]!=' ')

             {

                 flag=;

                 continue;

             }

             else

             {

                 string cur=paragraph.substr(beg,i-flag-beg);

                 simap[cur]++;

                 beg=i+;

                 flag=;

                 if(simap[cur]>max)

                 {

                     res=cur;

                     max=simap[cur];

                 }

             }

         }

         return res;

     }

 };