walking around circle of two sexes
Source: IMOC 2019 C3
August 19, 2021
combinatorics
Problem Statement
There are a total of boys and girls sitting in a big circle. Now, Dave wants to walk around the circle. For a start point, if at any time, one of the following two conditions holds:1. he doesn't see any girl
2. the number of boys he saw the number of girls he saw
Then we say this point is good. What is the maximum of with the property that there is at least one good point whenever the number of girls is ?