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