class Student extends Person{
	private int[] testScores;
    Student(String firstName, String lastName, int identification, int a[]){
        super(firstName,lastName,identification);
        this.testScores=a;
    }
    public String calculate(){
        int sum=0;
        for(int i=0; i<testScores.length; i++){
            sum+=testScores[i];
        }
        int avg=sum/testScores.length;
        if(avg>=90 && avg<=100){
            return "O";
        }
        else if(avg>=80 && avg<90){
            return "E";
        }
        else if(avg>=70 && avg<80){
            return "A";
        }
        else if(avg>=55 && avg<70){
            return "P";
        }
        else if(avg>=40 && avg<55){
            return "D";
        }
        return "T";
    }
}