diff --git a/day23.cpp b/day23.cpp
index 833c53f..f1b484e 100644
--- a/day23.cpp
+++ b/day23.cpp
@@ -32,8 +32,9 @@ auto Interact(Ethernet & ethernet, Machine & m, std::optional<Packet> p) -> void
       i.pos = p->first;
       StepInput(m, p->second);
       Interact(ethernet, m, {});
+    } else {
+      i.pos = -1; // no packet
     }
-    i.pos = -1; // no packet
   },
   [&](Output d) {
     auto x = StepOutput(m);
@@ -48,7 +49,8 @@ auto Interact(Ethernet & ethernet, Machine & m, std::optional<Packet> p) -> void
 } // namespace
 
 auto main() -> int {
-  auto machines = BuildNetwork(Machine{ParseStream(std::cin)});
+  std::ifstream fin { "/Users/emertens/Source/advent/inputs/2019/23.txt" };
+  auto machines = BuildNetwork(Machine{ParseStream(fin)});
   auto ethernet = Ethernet{};
 
   std::optional<ValueType> part1;