Need help in a codeforces Problem

Can Someone explain me this problem
Using bruteforce method

We have to choose a team such that no 2 volunteers have a problem with each other.

Since the number of volunteers, N = 16 is small we can iterate through all the subsets (2^16 = 65536) possible and check whether this subset satisfies the given condition.

Generating all the subsets can be done by bit manipulation.


Thank You So much!