How to declare a string stored inside a string variable to create a new variable in C++

    #include<iostream>
    using namespace std;
    struct student 
    {
    int roll_no;
    string branch;
    int grade; 
    };
   
    int main()
   {
   string s;
   cout <<"ENTER THE NAME OF THE STUDENT"<<endl;
   cin>>s;  
   struct student s;    //(HERE I WANT TO DECALRE THE NAME STORED INSIDE THE VARIABLE S)
   return 0;
   }