marks = []
for i in range(5):
while True:
try:
mark = float(input(f"Enter mark {i + 1}: "))
if 0 <= mark <= 100:
marks.append(mark)
break
else:
print("Mark must be between 0 and 100.")
except ValueError:
print("Invalid input.")
total = sum(marks)
average = total / 5
if average >= 90:
grade = 'A'
elif 80 <= average < 90:
grade = 'B'
elif 70 <= average < 80:
grade = 'C'
elif 60 <= average < 70:
grade = 'D'
else:
grade = 'F'
print(f"\nTotal: {total}")
print(f"Average: {average:.2f}")
print(f"Grade: {grade}")