void GradeCalculator()
{
   int num;

   cin >> num;

   vector<int> scores(num);
   vector<char> grades;

   cout << "Enter " << num << " scores: " << endl;

   int best = -1;

   for (int i = 0; i < num; i++) {
      cin >> scores[i];
      if (best < scores[i])
         best = scores[i];
   }

   for(int j = 0; j < num; j++)
   {
            if (scores[j] >= best - 10)
                grades[j] = 'A';
            else if (scores[j] >= best - 20)
                grades[j] = 'B';
            else if (scores[j] >= best - 30)
                grades[j] = 'C';
            else if (scores[j] >= best - 40)
                grades[j] = 'D';
            else grades[j] = 'F';

            int i = 0;
            cout << "Student " << (i+1) << " - Score: " << scores[i] << ", Letter: " << grades[i] << endl;
   }
}