If
x + y means x is a sister of y
x - y means x is a brother of y
x × y means x is a daughter of y
x ÷ y means x is the mother of y
then a + b - c × d ÷ e means
1
a, b, c,e are children of d,
2
a,b,c,d are children of e,
3
. b, c, d, e are children of a,
4
a, b, d are children of c