print @a1, @a2, @a3;;
A B A C D C D B 10 13 11 9 7 6 4 2 as ad ae at ag ak ao we

@order = sort{ $a1[ $a ] cmp $a1[ $b ] } 0 .. $#a1;;
print @a1[ @order ];;
A A B B C C D D

print @a2[ @order ];;
10 11 13 2 9 6 7 4

print @a3[ @order ];;
as ae ad we at ak ag ao