Single file promenade home.

sdr> heads lead right ; extend
| 4B>  1B>
| 
| 3G<  2G<
| 
| 4G>  1G>
| 
| 3B<  2B<
sdr> fan the top ; hinge
| 3B>  3G>  2B>  2G>
| 
| 4G<  4B<  1G<  1B<
sdr> trade
| 4G>  4B>  1G>  1B>
| 
| 3B<  3G<  2B<  2G<
sdr> roll twice
| 4G<  4B<  1G<  1B<
| 
| 3B>  3G>  2B>  2G>
sdr> /// note, we go to the #1 boy's home.
sdr> single file promenade home
|      3Gv  3Bv
| 
| 2B>            4G<
| 
| 2G>            4B<
| 
|      1B^  1G^
sdr> /exit