Were M2 and M4 acquired by M3 and acquired by a company that M1 acquired
SELECT count(*) WHERE {
?x0 a ns:business.employer .
?x0 ns:organization.organization.acquired_by/ns:business.acquisition.acquiring_company M1 .
M2 ns:organization.organization.acquired_by/ns:business.acquisition.acquiring_company ?x0 .
M2 ns:organization.organization.acquired_by/ns:business.acquisition.acquiring_company M3 .
M4 ns:organization.organization.acquired_by/ns:business.acquisition.acquiring_company ?x0 .
M4 ns:organization.organization.acquired_by/ns:business.acquisition.acquiring_company M3
}