prepare a java application that accomplishes the following tasks with built in exception handling:
1) Ask the number of homework assignment students have submitted in a semester

2) find out the letter grade the student has earned based on the average of these assignments.

1) Assume the full score for each assignment is 100. Student will get 0 for each unsubmitted assignment.

2) Student's letter grade is based on the average of all their assignments

90 -- 100 A

80 -- 89 B

70 -- 79 C

60 -- 69 D

0 -- 60 F