(unstack orange yellow robot)
(put-down orange robot)
(unstack yellow blue robot)
(put-down yellow robot)
(pick-up orange robot)
(stack orange yellow robot)
(unstack purple red robot)
(put-down purple robot)
(unstack red green robot)
(stack red orange robot)
(pick-up green robot)
(stack green red robot)
(pick-up blue robot)
(stack blue green robot)
(pick-up purple robot)
(stack purple blue robot)