Show the starting years shared by technicians from team "CLE" and "CWS".
return teams ;return #1 that is CLE ;return #1 that is CWS ;return technicians of #2 ;return technicians of #3 ;return starting years of #4 ;return starting years of #5 ;return starting years of both #6 and  #7
['select', 'filter', 'filter', 'project', 'project', 'project', 'project', 'intersection']