How many instructors are in the department with the highest budget, and what is their average salary?
return departments ;return budgets of  #1 ;return #1 where  #2 is  highest ;return instructors of  #3 ;return number of #4 ;return salaries of  #4 ;return average of  #6 ;return #5 ,   #7
['select', 'project', 'superlative', 'project', 'aggregate', 'project', 'aggregate', 'union']