If there are no less than three plain safety pins without any beads
return safety pins ;return #1 that are plain ;return beads ;return #2 that have beads ;return #2 besides  #4 ;return the  number of  #5 ;return if  #6 is at least three
['select', 'filter', 'select', 'filter', 'discard', 'aggregate', 'boolean']