average_grade(roster)
print ("Enter your grade for subject 1:");
grade1=int(input());
print ("Enter your grade for subject 2:");
grade2=int(input());
print ("Enter your grade for subject 3:");
grade3=int(input());
print ("Enter your grade for subject 4:");
grade4=int(input());
print ("Enter your grade for subject 5:");
grade5=int(input());
sum = (grade1 + grade2 + grade3 + grade4 +grade5)
average_grade = sum/5
return average_grade
