C++ i want to understand decimals [closed]

im trying to get a users int input in c++ and then from that input I am looking to show the decimal version of it, so for example the user enters 9281923, and then it shows 9.281923 as the answer. theres no limit to how many numbers a user can enter.

This is all i have so far:

 int main()
   {

      int num;
      cout << "Enter your number:" ;
      cin >> num;
   }

Any help is appreciate