diff --git a/Circuit.hs b/Circuit.hs
index 8a6e6f3..9442819 100644
--- a/Circuit.hs
+++ b/Circuit.hs
@@ -33,11 +33,14 @@ key_circuit_str = "19L:12R13R0#1R12R,14R0L0#4R9L,9R10R0#3L8L,2L17R0#5L9R,15R1L0#
 -- goal: Find a circuit with test_key_circ circ == True
 test_key_circ :: Circuit -> Bool
 test_key_circ circ = (key == execcirc circ)
+-- key: 11021210112101221
 
 factory0 = parseCircuit "0L:X0R0#X0R:0L"
 fact0_output = readstream "02120112100002120"
 test0 = fact0_output == execcirc factory0
 
+-- known server input stream (from factory "X::X")
+input = readstream "01202101210201202"
 
 data Circuit = Circuit { outPin :: Int, inPins :: [Int] } deriving (Eq)
 
@@ -123,7 +126,5 @@ execcirc circ = execfactory (circfactory circ) input
 readstream :: String -> [Int]
 readstream = map (\c -> read [c] :: Int)
 
-input = readstream "01202101210201202"
-
 key_input = [0,2,2,2,2,2,2,0,2,1,0,1,1,0,0,1,1]
 key = execfactory (circfactory key_circuit) key_input
diff --git a/circuit_delay.png b/circuit_delay.png
new file mode 100644
index 0000000..adc7073
Binary files /dev/null and b/circuit_delay.png differ