diff --git a/10/Main.idr b/10/Main.idr
new file mode 100644
index 0000000..9b731ec
--- /dev/null
+++ b/10/Main.idr
@@ -0,0 +1,284 @@
+import Data.Vect
+import Data.Fin
+import Data.String
+import Data.List
+import System.File.ReadWrite
+
+data Operation = Noop | Addx Int
+%name Operation op
+
+Show Operation where
+  show Noop = "Noop"
+  show (Addx i) = "Addx " ++ show i
+
+cycles : Operation -> Nat
+cycles Noop = 0
+cycles (Addx i) = 1
+
+parseOp : String -> Maybe Operation
+parseOp str =
+  case map trim . words $ str of
+    ["noop"] => Just Noop
+    ["addx", val] => do val <- parseInteger val
+                        pure (Addx val)
+    _ => Nothing
+
+parseOps : String -> Maybe (List Operation)
+parseOps str = traverse parseOp (lines str)
+
+data Pixel = On | Off
+%name Pixel pixel
+
+Show Pixel where
+  show On = "#"
+  show Off = "."
+
+record State where
+  constructor MkState
+  cycle : Nat
+  xRegister : Int
+  waitCycles : Nat
+  waitingOp : Maybe Operation
+%name State state
+
+Show State where
+  show (MkState cycle xRegister waitCycles waitingOp) =
+    "Cycle: " ++ show cycle ++ " X: " ++ show xRegister ++ " waitingOp: " ++ show waitingOp
+
+startState : State
+startState = MkState 0 1 0 Nothing
+
+isWaiting : State -> Bool
+isWaiting (MkState cycle xRegister waitCycles Nothing) = False
+isWaiting (MkState cycle xRegister waitCycles (Just x)) = True
+
+-- Tick the CPU, taking an operation off the stack if needed
+tick : State -> List Operation -> (State, List Operation)
+tick (MkState cycle xRegister 0 Nothing) [] =
+  (MkState (S cycle) xRegister 0 Nothing, [])
+tick (MkState cycle xRegister 0 (Just Noop)) [] =
+  (MkState (S cycle) xRegister 0 Nothing, [])
+tick (MkState cycle xRegister 0 (Just (Addx i))) [] =
+  (MkState (S cycle) (xRegister + i) 0 Nothing, [])
+tick (MkState cycle xRegister (S k) waitingOp) [] =
+  (MkState (S cycle) xRegister k waitingOp, [])
+tick (MkState cycle xRegister 0 Nothing) (x :: xs) =
+  (MkState (S cycle) xRegister (cycles x) (Just x), xs)
+tick (MkState cycle xRegister 0 (Just Noop)) (x :: xs) =
+  (MkState (S cycle) xRegister (cycles x) (Just x), xs)
+tick (MkState cycle xRegister 0 (Just (Addx i))) (x :: xs) =
+  (MkState (S cycle) (xRegister + i) (cycles x) (Just x), xs)
+tick (MkState cycle xRegister (S k) waitingOp) rest@(x :: xs) =
+  (MkState (S cycle) xRegister k waitingOp, rest)
+
+tickMultiple : State -> List Operation -> List State
+tickMultiple state [] =
+  if isWaiting state
+    then let (newState, rest) = tick state []
+             tail = tickMultiple newState rest
+         in state :: tail
+    else [state]
+tickMultiple state ops@(x :: xs) =
+  let (newState, rest) = tick state ops
+      tail = tickMultiple newState rest
+  in state :: tail
+
+extraSimple = """
+  noop
+  addx 3
+  addx -5
+"""
+
+simple = """
+  addx 15
+  addx -11
+  addx 6
+  addx -3
+  addx 5
+  addx -1
+  addx -8
+  addx 13
+  addx 4
+  noop
+  addx -1
+  addx 5
+  addx -1
+  addx 5
+  addx -1
+  addx 5
+  addx -1
+  addx 5
+  addx -1
+  addx -35
+  addx 1
+  addx 24
+  addx -19
+  addx 1
+  addx 16
+  addx -11
+  noop
+  noop
+  addx 21
+  addx -15
+  noop
+  noop
+  addx -3
+  addx 9
+  addx 1
+  addx -3
+  addx 8
+  addx 1
+  addx 5
+  noop
+  noop
+  noop
+  noop
+  noop
+  addx -36
+  noop
+  addx 1
+  addx 7
+  noop
+  noop
+  noop
+  addx 2
+  addx 6
+  noop
+  noop
+  noop
+  noop
+  noop
+  addx 1
+  noop
+  noop
+  addx 7
+  addx 1
+  noop
+  addx -13
+  addx 13
+  addx 7
+  noop
+  addx 1
+  addx -33
+  noop
+  noop
+  noop
+  addx 2
+  noop
+  noop
+  noop
+  addx 8
+  noop
+  addx -1
+  addx 2
+  addx 1
+  noop
+  addx 17
+  addx -9
+  addx 1
+  addx 1
+  addx -3
+  addx 11
+  noop
+  noop
+  addx 1
+  noop
+  addx 1
+  noop
+  noop
+  addx -13
+  addx -19
+  addx 1
+  addx 3
+  addx 26
+  addx -30
+  addx 12
+  addx -1
+  addx 3
+  addx 1
+  noop
+  noop
+  noop
+  addx -9
+  addx 18
+  addx 1
+  addx 2
+  noop
+  noop
+  addx 9
+  noop
+  noop
+  noop
+  addx -1
+  addx 2
+  addx -37
+  addx 1
+  addx 3
+  noop
+  addx 15
+  addx -21
+  addx 22
+  addx -6
+  addx 1
+  noop
+  addx 2
+  addx 1
+  noop
+  addx -10
+  noop
+  noop
+  addx 20
+  addx 1
+  addx 2
+  addx 2
+  addx -6
+  addx -11
+  noop
+  noop
+  noop
+  """
+
+indexes : List Nat -> List a -> Maybe (List (Nat, a))
+indexes [] xs = Just []
+indexes (x :: ys) xs =
+  do idx <- natToFin x (length xs)
+     let value = index' xs idx
+     rest <- indexes ys xs
+     pure ((x, value) :: rest)
+
+
+cycle : (start : Nat) -> (inc : Nat) -> (end : Nat) -> List Nat
+cycle start inc end =
+  if start >= end
+    then []
+    else start :: cycle (assert_smaller start (start + inc)) inc end
+
+testPart1 : IO ()
+testPart1 =
+  do Just ops <- pure $ parseOps simple
+       | Nothing => putStrLn "Error parsing ops"
+     let states = tickMultiple startState ops
+     let idxs = cycle 20 40 (length states)
+     Just selectedStates <- pure . map (map snd) $ indexes idxs states
+       | Nothing => putStrLn "Not enough cycles"
+     putStrLn "Selected States:"
+     traverse_ printLn selectedStates
+     let totalSignal = sum . map (\x => (xRegister x) * (cast (cycle x))) $ selectedStates
+     putStrLn ("Total Signal Strength: " ++ show totalSignal)
+
+part1 : List Operation -> Maybe Int
+part1 ops =
+  let states = tickMultiple startState ops in
+  do selectedStates <- indexes (cycle 20 40 (length states)) states
+     let totalSignal = sum . map (\x => (xRegister x) * (cast (cycle x))) . map snd $ selectedStates
+     pure totalSignal
+
+main : IO ()
+main =
+  do Right file <- readFile "input"
+       | Left err => printLn err
+     Just ops <- pure (parseOps file)
+       | Nothing => putStrLn "Error parsing ops"
+     Just part1Result <- pure (part1 ops)
+       | Nothing => putStrLn "Error in part1"
+     putStrLn ("Part 1: " ++ show part1Result)
diff --git a/10/input b/10/input
new file mode 100644
index 0000000..89ec3f1
--- /dev/null
+++ b/10/input
@@ -0,0 +1,137 @@
+noop
+addx 7
+addx -1
+addx -1
+addx 5
+noop
+noop
+addx 1
+addx 3
+addx 2
+noop
+addx 2
+addx 5
+addx 2
+addx 10
+addx -9
+addx 4
+noop
+noop
+noop
+addx 3
+addx 5
+addx -40
+addx 26
+addx -23
+addx 2
+addx 5
+addx 26
+addx -35
+addx 12
+addx 2
+addx 17
+addx -10
+addx 3
+noop
+addx 2
+addx 3
+noop
+addx 2
+addx 3
+noop
+addx 2
+addx 2
+addx -39
+noop
+addx 15
+addx -12
+addx 2
+addx 10
+noop
+addx -1
+addx -2
+noop
+addx 5
+noop
+addx 5
+noop
+noop
+addx 1
+addx 4
+addx -25
+addx 26
+addx 2
+addx 5
+addx 2
+noop
+addx -3
+addx -32
+addx 1
+addx 4
+addx -2
+addx 3
+noop
+noop
+addx 3
+noop
+addx 6
+addx -17
+addx 27
+addx -7
+addx 5
+addx 2
+addx 3
+addx -2
+addx 4
+noop
+noop
+addx 5
+addx 2
+addx -39
+noop
+noop
+addx 2
+addx 5
+addx 3
+addx -2
+addx 2
+addx 11
+addx -4
+addx -5
+noop
+addx 10
+addx -18
+addx 19
+addx 2
+addx 5
+addx 2
+addx 2
+addx 3
+addx -2
+addx 2
+addx -37
+noop
+addx 5
+addx 4
+addx -1
+noop
+addx 4
+noop
+noop
+addx 1
+addx 4
+noop
+addx 1
+addx 2
+noop
+addx 3
+addx 5
+noop
+addx -3
+addx 5
+addx 5
+addx 2
+addx 3
+noop
+addx -32
+noop