Were M1 and M3 acquired by M2 and acquired by M0 's employer
SELECT count(*) WHERE {
?x0 ns:business.employer.employees/ns:business.employment_tenure.person M0 .
M1 ns:organization.organization.acquired_by/ns:business.acquisition.acquiring_company ?x0 .
M1 ns:organization.organization.acquired_by/ns:business.acquisition.acquiring_company M2 .
M3 ns:organization.organization.acquired_by/ns:business.acquisition.acquiring_company ?x0 .
M3 ns:organization.organization.acquired_by/ns:business.acquisition.acquiring_company M2
}