Show the names of phones that are on market with number of shops greater than 50.
return market ;return shops of #1 ;return the  number of  #2 ;return #1 where #3 is higher than 50 ;return the  names of #4 ;return the  phone of #4 ;return #5 ,  #6
['select', 'project', 'aggregate', 'comparative', 'project', 'project', 'union']