Fix

Signed-off-by: Thynson <lanxingcan@gmail.com>
Change

Signed-off-by: Thynson <lanxingcan@gmail.com>
balance difficulty

Signed-off-by: Thynson <lanxingcan@gmail.com>
change

Signed-off-by: Thynson <lanxingcan@gmail.com>
Fix beats

Signed-off-by: Thynson <lanxingcan@gmail.com>
complete timeline

Signed-off-by: Thynson <lanxingcan@gmail.com>