import java.util.*;
import java.text.DecimalFormat;

public class Prog8
{
  public static void main(String [] args)
  {

    final int STUD_ID_MAX = 9999;
    final int STUD_ID_MIN = 1111;
    final int EXAM_SCORE_MAX = 100;
    final int EXAM_SCORE_MIN = 0;

    String studName;
    String Grade;
    int studID;
    int Exam;
    int invalidCounter = 0;
    int validCounter = 0;
    int examMin = 100;
    int examMax = 0;
    int examSum = 0;
    double avg;
    double validPercent;
    double invalidPercent;


    Scanner inFile = new Scanner(System.in);

    System.out.println("~~~Exam Report~~~\n");
    System.out.println("Student ID  N a m e  Exam  Grade");
    System.out.println("----------  -------  ----  -----");

    while(inFile.hasNextInt())  //Beginning of loop
{
    studID = inFile.nextInt();
    studName = inFile.next();
    Exam = inFile.nextInt();
    inFile.nextLine();

    if ((studID < STUD_ID_MIN || studID > STUD_ID_MAX) //Invalid Data
      || (Exam < EXAM_SCORE_MIN || Exam > EXAM_SCORE_MAX))  {

     invalidCounter++;
     System.out.println(studID + "\t" + studName + "\t" + Exam + "\t" + "~~~ Invalid");

  } else {  //Valid data, beginning of if/else to decide score

    if (Exam == 100 && Exam>= 97)  {
      Grade = "A+";

  } else if (Exam <= 96 && Exam > 93)  {
      Grade = "A";

  } else if (Exam <= 93 && Exam > 89)  {
      Grade = "A-";

  } else if (Exam <= 89 && Exam >= 87)  {
      Grade = "B+";

  } else if (Exam <= 86 && Exam > 83)  {
      Grade = "B";

  } else if (Exam <= 83 && Exam > 79)  {
      Grade = "B-";

  } else if (Exam <= 79 && Exam >= 77)  {
      Grade = "C+";

  } else if (Exam <= 76 && Exam > 73)  {
      Grade = "C";

  } else if (Exam <= 73 && Exam > 69)  {
      Grade = "C-";

  } else if (Exam <= 69 && Exam >= 67)  {
      Grade = "D+";

  } else if (Exam <= 66 && Exam > 63)  {
      Grade = "D";

  } else if (Exam <= 63 && Exam > 59)  {
      Grade = "D-";

  } else {
      Grade = "F";
    }

   validCounter++;
   examSum += Exam;

  System.out.println(studID + "\t" + studName + "\t" + Exam + "\t" + Grade);
  }  //End of if/else to decide score

    if (Exam <= EXAM_SCORE_MAX && Exam >= EXAM_SCORE_MIN)  { //Deciding max/min scores
      if (Exam > examMax) {
         examMax = Exam;
    } if (Exam < examMin)  {
         examMin = Exam;

  } else { }
    }  //End of nested if and if/else to decide max/min
  }  //End of loop

 if (validCounter != 0)  {
  avg = (examSum / validCounter);
  validPercent = ((validCounter / (validCounter + invalidCounter)) * 100.0);
  invalidPercent = ((invalidCounter / (validCounter + invalidCounter)) * 100.0);

    System.out.println(" ");
    System.out.println("Exam MAX is: " + examMax);
    System.out.println("Exam MIN is: " + examMin);
    System.out.println(" ");
    System.out.println("Exam Average is: " + avg);
    System.out.println("Number of valid exams: " + validCounter);
    System.out.println("Number of invalid exams: " + invalidCounter);
    System.out.println("Valid Data: " + validPercent + "%");
    System.out.println("Invalid Data: " + invalidPercent + "%");

  } else {
    System.out.println(" ");
    System.out.println("No valid data! No Max, Min, Avg for exam(s)!");
    System.out.println("Number of valid exams: " + validCounter);
    System.out.println("Number of invalid exams: " + invalidCounter);
  }
  System.out.println("~~~end~~~");
 }
}