question: Was M1 acquired by M2 , M3 , M4 , and M5 , acquired by a company , and acquired by M6
query: SELECT count(*) WHERE {
  ?x0 a ns:business.employer .
  M1 ns:organization.organization.acquired_by/ns:business.acquisition.acquiring_company ?x0 .
  M1 ns:organization.organization.acquired_by/ns:business.acquisition.acquiring_company M2 .
  M1 ns:organization.organization.acquired_by/ns:business.acquisition.acquiring_company M3 .
  M1 ns:organization.organization.acquired_by/ns:business.acquisition.acquiring_company M4 .
  M1 ns:organization.organization.acquired_by/ns:business.acquisition.acquiring_company M5 .
  M1 ns:organization.organization.acquired_by/ns:business.acquisition.acquiring_company M6
  }