ANSWER: 5 apples
Lilian has 12 then 6 (gives 6 to Sebastian)
Sebastian has 6 then 4 (gives 2 to Jose)
Maria has 6 then 4 (gives 2 to Jose)
Sebastian has 4 then 2 (gives 2 to Maria)
Maria has 6 then 5 (gives 1 to Lilian)
Lilian ends with 7 apples
Maria ends with 5 apples
Sebastian ends with 2 apples
Jose ends with 4 apples