Algorithms and Programming for High Schoolers

When and where: Addis Ababa, July 18 - August 12, 2016 (European calendar)

For more information, solve the below puzzle to get a number X, then email algorithmsX@seas.harvard.edu.

Puzzle:

700 people enter a room, and everybody shakes everybody's hand exactly once. How many handshakes are there total?
(for example if there were 2 people in the room instead of 700, the answer would be 1)