It has to be:
Leg 1: Valparaiso-Santiago (12 teams, 1 eliminated)
Leg 2: Santiago-Puento Varas (11 teams, Grandmother/Granddaughter eliminated)
Leg 3: Puento Varas-Bariloche,Argentina (10 teams, 1 eliminated)
Leg 4: Bariloche-Buenos Aires,Argentina (9 teams, 1 eliminated)