Input (grade 11): At the appropriate moment, the hen cuckoo flies down to the Reed Warblers' nest, pushes one Reed Warbler egg out of the nest, lays an egg and flies off.
Output (grade 12): When the female cuckoo thinks it is the right moment she will fly down to the reed warblers' nest, pushes one reed warbler egg out of the nest, lays her egg and flies off.