Today's assignment: Using GRE- style problem solving to help sort out the nighttime rituals of a girl with borderline OCD.

Alli can only take out her contact lens when her hands are clean.
Alli's hands get "dirty" when she brushes her teeth.
Alli likes to brush her teeth before she washes her face.
Alli's hands are only clean after washing her face and after using the toilet.
Alli can't wash her face with the contact lens in, because she gets scared it will fall out.

In what precise order must Alli perform her rituals?