Peggy takes either path A or B ; Victor is not allowed to see which path she takes . Then , Victor enters the cave and shouts the name of the path he wants her to use to return , either A or B , chosen at random .
They label the left and right paths from the entrance A and B. Peggy randomly takes either path A or B . Then , Victor enters the cave and shouts the name of the path he wants her to use to return , either A or B , chosen at random .