/***************************************************
Grading

A school tracks grades as A, B, C, D or E (not F).
A students GPA is a number between 0 and 4, which
you calculate by averaging the grades - an A is
given 4 points, down to an E which is given 0 points.

Write a program that reads in 4 letter grades (a 
student's first semester) and prints out his GPA.
***************************************************/
#include <iostream>
using namespace std;

int main()
{
  // Read in four grades
  cout << "Enter four grades: ";
  char g1, g2, g3, g4;
  cin >> g1 >> g2 >> g3 >> g4;
  
  // Compute weights for the four grades
  int w1, w2, w3, w4;
  w1 = 'E' - g1;
  w2 = 'E' - g2;
  w3 = 'E' - g3;
  w4 = 'E' - g4;

  // Compute GPA
  double a;
  a = double(w1 + w2 + w3 + w4)/4.0;

  // Print out GPA
  cout << "GPA is " << a << endl;

  return 0;
}