// import java.util.*;
class Student{
private String stype;
private String name;
private int id;
Student(String stype,String name,int id)
{
this.stype = stype;
this.name = name;
this.id = id;
}

    public String getstype()
    {
return stype;

}

public String getname()
{
return name;
}

public int getid()
{
return id;
}
}

class Main
{
public static void main(String []args)
{
Scanner sc = new Scanner(System.in);
String stype = sc.nextLine();
if(!(stype.equals("Undergraduate")) && !(stype.equals("Postgraduate")))
{
System.out.println("Invalid input");
return;
}
String name = sc.nextLine();
int id = sc.nextInt();
int grade =sc.nextInt();
int a[] = new int[grade];
for(int i=0;i<grade;i++)
{
if(sc.hasNextInt())
{
a[i]=sc.nextInt();
if(a[i]<0)
{
System.out.println("Invalid input");
return;
 }
}
else
{
System.out.println("Invalid input");
return;
}
}
Student s1 = new Student(stype,name,id);
System.out.printf("%.2f",avg(a,grade));
 }
static float avg(int a[],int grade)
{
float sum=0;
for(int i=0;i<grade;i++)
{
sum+=a[i];
}
float res = sum/grade;
return res;
}
}