"""
Johnny is a farmer and he annually holds a beet farmers convention "Drop the 
Beet".  Every year he takes photos of farmers handshaking. Johnny knows that 
no two farmers handshake more than once. He also knows that some of the 
possible handshake combinations may not happen.

However, Johnny would like to know the minimal amount of people that 
participated this year just by counting all the handshakes.

Help Johnny by writing a function, that takes the amount of handshakes and 
returns the minimal amount of people needed to perform these handshakes (a pair 
of farmers handshake only once).
"""

def get_participants(n):
    return n * (n – 1) // 2
