I came to school...

Woojin came to school and saw the pencil case I made and stole not 1, but 12 of my favorite mechanical pencils. The next day, he saw that I was gone, so I, who was always the 19th student to come to school, came first and searched my locker, my pencil case, my drawers, and my bag, but they weren't there... So while I was looking for them, Woojin came and asked me, "Jin-ah, did you steal my 12 favorite mechanical pencils?" Woojin stuttered and said, "Oh... no, I... I didn't steal them... uh." So