average using the 4 highest scores of the 5 enterd

need help to find the averge of the 4 highest test scores
out of the 5 that were entered i think i need a func but i'm having trouble setting it  up..

#include <iostream>
#include <iomanip>
using namespace std;


void EvalGrade ( int Grade);
void FindAve (float Ave);
void Minimum(float,float,float,float,float);
{
  char letterGrade;
please email me a911hoe@msn.com with answ
 

   switch ( Grade/10)
   {
      case 10:
        case 9:
           
              letterGrade = 'A';
                break;

        case 8:
                 letterGrade = 'B';
                 break;

        case 7:
                letterGrade = 'C';
                break;

        case 6:
                letterGrade = 'D';
                break;

        case 5:
        case 4:
        case 3:
        case 2:
        case 1:
        case 0:
                letterGrade = 'F';



   }

   cout << "The letter grade is: " << letterGrade << endl;
   cout << "The Average is :" << ave << endl;
}

void main()

 {

     float Minimum(float test1,float test2, float test3, float test4, float test5)

         if (test1 < test2 && test1 < test5)
                return test1;
          if (test2 < test1 && test2 < test5)
               return test2;
          if (test3 < test1 && test3 < test5)
               return test3;
          if (test4 < test1 && test4 < test5)
               return test4;
          if (test5 < test1 && test5 <test4)
               return test5;

      FindAve

        Ave = test1 + test2+ test3 +test4 + test5 - Minimum / 4;
     
     return Ave


  int Grade;

   cout <<"Please enter Test 1\n ";
   cin >> Grade;

   EvalGrade ( Grade);

   cout << "Please enter Test 2\n";
   cin >> Grade;

   EvalGrade ( Grade);

   cout << "Please enter Test 3\n";
   cin >> Grade;

   EvalGrade ( Grade);

   cout << "Please enter Test 4\n";
   cin >> Grade;

   EvalGrade ( Grade);

   cout << "Please enter Test 5\n";
   cin >> Grade;

    EvalGrade ( Grade);
 


}