Who is Hanka, Zuzka, Mana, and Andula from Under a Cruel Star: A Life in Prague 1941-1968 and what is their importance?

The four named women are friends of Kovály during her final days at Auschwitz, and together the five are forcibly evacuated westward to avoid liberation by the approaching Russian army. When the evacuation detail nears Prague, the five women decide to attempt escape and one night they flee. Andula is shot in the escape process; the other four women make good their escape. Mana initially argues that they should return to captivity rather than face an uncertain future. Zuzka's home town is nearest and the three other women are cared for briefly by Zuzka's relatives. Mana is ill and remains with Zuzka while Hanka and Kovály proceed to Prague where they, too, separate. The ultimate fates of Hanka, Zuzka, and Mana are not related in the book.