#include <iostream>

using namespace std;

const int maxNumberOfGrades = 500;

int main()
{
 

  int i;


  int grades[maxNumberOfGrades];

  int numberOfGrades;

  cout << "How many grades? ";
  cin >> numberOfGrades;

  for (i=0;i<numberOfGrades;i++) {
    cout << "Input grade " << i << ": ";
    cin >> grades[i];
    //..
  } 


  int sum=0;
  for (i=0;i<numberOfGrades;i++) {
    sum+=grades[i];  // sum = sum+grades[i];
  }
  float average = (static_cast<float>(sum)/numberOfGrades);




  cout << "The average grade is " << average << endl;

  return 0;
}