Remove two children
who are occupying adjoining
chairs and place them in two empty chairs, *making
them first
change sides*; then remove a
second pair of children from
adjoining chairs and place them in the two now vacant, making them
change sides; and so on, until all the boys are together and all the
girls together, with the two vacant chairs at one end as at
present.

You must do this in
five
moves.

The two children
must always be taken from chairs
that are next to one another; and remember the important point of
making the two children change sides, as
this latter is the distinctive feature of the puzzle.

By "change
sides" you first move 1 and 2 to the vacant chairs, then the
first (the outside) chair will be occupied by 2 and the second one by 1.