Hi, I was asked to calculate the time complexity of the following code, can anyone help please?

``` sib = [] if person_index(person, family) is None: return sib else: fa = father(person, family) ma = mother(person, family) if fa is not None: fa_child = children(fa, family) for i in range(len(fa_child)): if fa_child[i] not in sib and fa_child[i] != person: sib.append(fa_child[i]) elif ma is not None: ma_child = children(ma, family) for j in range(len(ma_child)): if ma_child[j] not in sib and ma_child[j] != person: sib.append(ma_child[j]) return sib ```