+28 Merlin is in charge of seating groups of knights around a circular table. Knights enter alone or in groups, and Merlin places them in a random set of adjacent seats at the table. If the knights arrive in groups of 2, 7, 3, 6, 1, 5, 2 and 1 (in that order), what is the minimum number of seats that the table must have to ensure each group is guaranteed to get seated properly?
