diff --git a/16/part2.pl b/16/part2.pl
index 41f47c0..58b8863 100644
--- a/16/part2.pl
+++ b/16/part2.pl
@@ -5,12 +5,15 @@ main([FileName|_]) :-
     input(FileName, Map),
     length(Map, Height), MaxX is Height - 1,
     Map = [Row|_], length(Row, Width), MaxY is Width - 1,
-    findall(N, (between(0, MaxX, X), propagate(Map, [X-0-3], End), count(End, N)), N1), nl,
-    findall(N, (between(0, MaxX, X), propagate(Map, [X-MaxY-1], End), count(End, N)), N2), nl,
-    findall(N, (between(0, MaxY, Y), propagate(Map, [0-Y-0], End), count(End, N)), N3), nl,
-    findall(N, (between(0, MaxY, Y), propagate(Map, [MaxX-Y-2], End), count(End, N)), N4), nl,
-    append([N1, N2, N3, N4], Ns), max_list(Ns, Answer),
-    write(Answer), nl.
+    findall([X-0-3], between(0, MaxX, X), S1),
+    findall([X-MaxY-1], between(0, MaxX, X), S2),
+    findall([0-Y-0], between(0, MaxY, Y), S3),
+    findall([MaxX-Y-2], between(0, MaxY, Y), S4),
+    append([S1, S2, S3, S4], Starts),
+    concurrent_maplist(
+        {Map}/[S, N]>>(propagate(Map, S, End), count(End, N)), Starts, Ns),
+    max_list(Ns, Answer),
+    nl, write(Answer), nl.
 
 count(Map, X) :-
     findall(1, (nth0(_, Map, Row), nth0(_, Row, _-D), \+ D = [0,0,0,0]), Ls),