Sinuous Trail S Rank non Lethal shotgun [Ready or Not] [No Commentary]

Need to be patient on this stage. First I clear all enemy outdoor. Look at the door if there any door open inside. If there is, there probably enemy inside. If you not see any enemy, Let AI to cover you when you close the door. When closing opening door, back to outside and close the door. Repeat for every outdoor door. Check again if the door you close is open. If all safe, I like to use the lobby using side door. Clear 1st floor except server room because there so many doorways without door. Then going to 2nd floor. Let either server room at the east or the middle server as the last room to check.