1. Marc Garneau Collegiate Institute, Toronto, Ontario, M3C 1B3, Canada Email address:
2. Princeton High School, Princeton, New Jersey, 08540, USA Email address:
3. Department of Astronomy, University of Michigan, Ann Arbor, Michigan, 48109, USA Email address:
4. Department of Mathematics and Statistics, Williams College, Williamstown, Massachusetts, 01267, USA Email address:
5. Shanghai Starriver Bilingual School, Shanghai, 201108, China Email address:
6. Concord Academy, Concord, Massachusetts, 01742, USA Email address:
7. Department of Mathematics and Statistics, Williams College, Williamstown, Massachusetts, 01267, USA Email address: Email address:
8. Taft school, Watertown, Connecticut, 06795, USA Email address:
9. Mathematical Institute, University of Oxford, Oxford, United Kingdom Email address:
10. Department of Mathematics, University of Michigan, Ann Arbor, Michigan, 48109, USA Email address: