diff --git a/2019/24.cpp b/2019/24.cpp
index 9b9abb9..4be6e90 100644
--- a/2019/24.cpp
+++ b/2019/24.cpp
@@ -62,23 +62,23 @@ struct Neighbor2 {
   auto operator()(C3 cd, auto f) const -> void {
     auto const [c,d] = cd;
 
-    auto left_neighbors = [&f](Coord c, std::int64_t d, auto k_, auto k) {
-      c = k_(c);
-      if (c.x == 1 && c.y == 0) {
+    auto left_neighbors = [&](auto k_, auto k) {
+      auto c_ = k_(c);
+      if (c_.x == 1 && c_.y == 0) {
         for (std::int64_t yi = -2; yi <= 2; yi++) {
           f({k({2,yi}),d+1});
         }
-      } else if (c.x > -2) {
-        f({k(Left(c)),d});
+      } else if (c_.x > -2) {
+        f({k(Left(c_)),d});
       } else {
         f({k({-1,0}),d-1});
       }
     };
     auto id = [](Coord i) { return i; };
-    left_neighbors(c, d, id, id);
-    left_neighbors(c, d, Turn180, Turn180);
-    left_neighbors(c, d, CW, CCW);
-    left_neighbors(c, d, CCW, CW);
+    left_neighbors(id, id);
+    left_neighbors(Turn180, Turn180);
+    left_neighbors(CW, CCW);
+    left_neighbors(CCW, CW);
   }
 };