text: //write include required statements
  #include<string>
  
  /*Write a function prototype named get_grade_points that accepts a 
  string letter_grade and returns an int */
  int get_grade_points(std::string letter_grade);
  
  
  /*Write a function prototype with name calculate_gpa that accepts an int named credit_hours and
  an double named credit_points returns double*/  
  double calculate_gpa(int credit_hours, double credit_points);
  
  