Unit 1. Net Search. Family Puzzle 2

[macgarcia]

The following people were at a family gathering: a grandfather, a grandmother, two fathers, two mothers, four children, three grandchildren, one brother, two sisters, two sons, two daughters, one father-in-law, one mother-in-law, and one daughter-in-law. What is the smallest number of people who could have been at the gathering? (Hint: The answer is not 23.)