I don't remember, but someone mentioned that there were lots of similar submissions to E1, when I looked at the suspicious submissions, they had one thing in common: memory consumed was equal to 8089600 bytes, so I ran some python and obtained these submissions(lets see how many are detected by plag-checker):

277426958, 277425890, 277425852, 277424914, 277424565, 277418774, 277418655, 277418511, 277418081, 277417714, 277417556, 277417035, 277416988, 277415986, 277415655, 277415207, 277414924, 277414655, 277413989, 277413413, 277413097, 277412884, 277412728, 277412417 rest I am commenting due to word limit