#include <iostream>
using namespace std;

int Exam[100];
float average;
int highest;
int lowest;
int Students;
int Grade;
int GradeSum=0;
int Average;
bool FirstTime;
bool FirstTime2;
int u;

int main()

{

    cout << "Students : ";
    cin >> Students;
    FirstTime = true;
    FirstTime2 = true;

    for (int i=0; i < Students;i++)
    {
        cout << "Enter Grades : ";
        cin >> Grade;
        GradeSum = GradeSum + Grade;
        if (Grade >= 90)
        {  if (FirstTime == true){
                Grade = highest;
                FirstTime = false;
            }
        if ( Grade > highest)
            Grade = highest;
            Exam[u] = 'A';
            u++;
            cout << "A";
        cout << endl;
        }
        if (Grade >= 80 && Grade <= 89)
        {  cout << "B" << endl;
        Exam[u] = 'B';
            u++;}
        if (Grade >= 70 && Grade <=79)
        { cout << "C" << endl;
        Exam[u] = 'C';
            u++;}
        if (Grade >= 60 && Grade <= 69){
            cout << "D" << endl;
            Exam[u] = 'D';
            u++;}
        if (Grade <= 59)
        {     if (FirstTime2 == true)
            {
                Grade = lowest;
                FirstTime2 = false;
            }
        if (Grade < lowest)
           Grade = lowest;

            cout << "F" << endl;
            Exam[u] = 'F';
            u++;
        }
    }
    cout << endl;
    cout << endl;
   cout << Exam[Students];

    Average = GradeSum/Students;
    cout << "Average : " << Average;
    cout << "Highest : " << highest;
    cout << "Lowest : " << lowest;



    return 0;
}