Alphabetical Build Order

Six build targets with dependency edges u → v meaning u must be built before v:

1→3, 2→3, 3→5, 4→5, 2→4, 1→6, 6→5

Starting in-degrees:

target	1	2	3	4	5	6
in-degree	0	0	2	1	3	1

You run Kahn's algorithm with a min-heap in place of the queue, so among all ready targets you always take the smallest number. Which order comes out?