assignment 2

i upload the manual
Revert "assignment 2"

This reverts commit a5c1fdfce38e350599a96ff0f7195ce465607ca9.
Revert "Revert "assignment 2""

This reverts commit 5dc007a915bdb11aa6b7430b757a3b3f287d0781.
java code

i upload my java code
Revert "java code"

This reverts commit 5a411d8a9f9fecfb2eaa1b1b7839e38f92301217.