diff --git a/build.gradle.kts b/build.gradle.kts
index cb249d4..2cf0978 100644
--- a/build.gradle.kts
+++ b/build.gradle.kts
@@ -2,8 +2,9 @@ import org.jetbrains.kotlin.gradle.tasks.KotlinJvmCompile
 
 plugins {
     kotlin("jvm")
-    id("com.github.johnrengelman.shadow")
+    id("com.gradleup.shadow")
     id("org.jmailen.kotlinter")
+    id("com.adarshr.test-logger")
     application
 }
 
@@ -35,10 +36,6 @@ tasks.test {
     maxHeapSize = "20g"
 }
 
-tasks.withType<KotlinJvmCompile> {
-    kotlinOptions.jvmTarget = "21"
-}
-
 tasks.withType<JavaExec> {
     standardInput = System.`in`
 }
diff --git a/kls_database.db b/kls_database.db
deleted file mode 100644
index 68fdb7b..0000000
Binary files a/kls_database.db and /dev/null differ
diff --git a/src/main/kotlin/cz/glubo/adventofcode/Main.kt b/src/main/kotlin/cz/glubo/adventofcode/Main.kt
index bc226ee..430b350 100644
--- a/src/main/kotlin/cz/glubo/adventofcode/Main.kt
+++ b/src/main/kotlin/cz/glubo/adventofcode/Main.kt
@@ -60,6 +60,8 @@ import cz.glubo.adventofcode.y2024.day15.y2024day15part1
 import cz.glubo.adventofcode.y2024.day15.y2024day15part2
 import cz.glubo.adventofcode.y2024.day16.y2024day16part1
 import cz.glubo.adventofcode.y2024.day16.y2024day16part2
+import cz.glubo.adventofcode.y2024.day17.y2024day17part1
+import cz.glubo.adventofcode.y2024.day17.y2024day17part2
 import cz.glubo.adventofcode.y2024.day2.y2024day2part1
 import cz.glubo.adventofcode.y2024.day2.y2024day2part2
 import cz.glubo.adventofcode.y2024.day3.y2024day3part1
@@ -137,6 +139,13 @@ class InputToLongCommand(
     override suspend fun execute(input: Input) = action(input)
 }
 
+@Command(mixinStandardHelpOptions = true)
+class InputToStringCommand(
+    private val action: suspend (input: Input) -> String,
+) : InputCommand<String>() {
+    override suspend fun execute(input: Input) = action(input)
+}
+
 @Command(mixinStandardHelpOptions = true)
 class LinesToIntCommand(
     private val action: suspend (Flow<String>) -> Int,
@@ -252,6 +261,8 @@ fun main(args: Array<String>) {
             "2024day15p2" to InputToLongCommand { y2024day15part2(it) },
             "2024day16p1" to InputToLongCommand { y2024day16part1(it) },
             "2024day16p2" to InputToLongCommand { y2024day16part2(it) },
+            "2024day17p1" to InputToStringCommand { y2024day17part1(it) },
+            "2024day17p2" to InputToLongCommand { y2024day17part2(it).toLong() },
         )
 
     val cmd = CommandLine(MyHelpCommand())
diff --git a/src/main/kotlin/cz/glubo/adventofcode/utils/Utils.kt b/src/main/kotlin/cz/glubo/adventofcode/utils/Utils.kt
index fdabf84..7f78ad9 100644
--- a/src/main/kotlin/cz/glubo/adventofcode/utils/Utils.kt
+++ b/src/main/kotlin/cz/glubo/adventofcode/utils/Utils.kt
@@ -261,3 +261,7 @@ fun IntRange.split(boundary: Int): Pair<IntRange?, IntRange?> =
     }
 
 fun Int?.orMax() = this ?: Int.MAX_VALUE
+
+fun <T> List<T>.isSame(other: List<T>) = (this.size == other.size) && this.indices.all {
+    this[it] == other[it]
+}
diff --git a/src/main/kotlin/cz/glubo/adventofcode/y2023/day4/Day4.kt b/src/main/kotlin/cz/glubo/adventofcode/y2023/day4/Day4.kt
index d483df0..f2ae627 100644
--- a/src/main/kotlin/cz/glubo/adventofcode/y2023/day4/Day4.kt
+++ b/src/main/kotlin/cz/glubo/adventofcode/y2023/day4/Day4.kt
@@ -77,5 +77,6 @@ fun pow2(n: Int): Int =
     } else if (n == 0) {
         1
     } else {
-        (0..<n).fold(1) { acc: Int, _: Int -> acc * 2 }
+//        (0..<n).fold(1) { acc: Int, _: Int -> acc * 2 }
+        1.shl(n)
     }
diff --git a/src/main/kotlin/cz/glubo/adventofcode/y2024/day17/Day17.kt b/src/main/kotlin/cz/glubo/adventofcode/y2024/day17/Day17.kt
new file mode 100644
index 0000000..801daf6
--- /dev/null
+++ b/src/main/kotlin/cz/glubo/adventofcode/y2024/day17/Day17.kt
@@ -0,0 +1,235 @@
+package cz.glubo.adventofcode.y2024.day17
+
+import cz.glubo.adventofcode.utils.input.Input
+import cz.glubo.adventofcode.utils.isSame
+import cz.glubo.adventofcode.y2024.day17.ParameterType.COMBO
+import cz.glubo.adventofcode.y2024.day17.ParameterType.LITERAL
+import io.klogging.noCoLogger
+import kotlinx.coroutines.flow.toList
+import java.math.BigInteger
+
+val logger = noCoLogger({}.javaClass.toString())
+
+enum class ParameterType {
+    LITERAL,
+    COMBO,
+}
+
+enum class OPCODE(
+    val opcode: Int,
+    val type: ParameterType,
+) {
+    ADV(0, COMBO),
+    BXL(1, LITERAL),
+    BST(2, COMBO),
+    JNZ(3, LITERAL),
+    BXC(4, LITERAL),
+    OUT(5, COMBO),
+    BDV(6, COMBO),
+    CDV(7, COMBO),
+}
+
+data class State(
+    var A: Long,
+    var B: Long,
+    var C: Long,
+    var pointer: Int,
+    var output: String,
+)
+
+typealias Program = List<Pair<OPCODE, Int>>
+
+fun combo(
+    state: State,
+    param: Int,
+): Long =
+    when (param) {
+        0, 1, 2, 3 -> param.toLong()
+        4 -> state.A
+        5 -> state.B
+        6 -> state.C
+        7 -> error("reserved")
+        else -> error("unknow combo value $param")
+    }
+
+infix fun String.join(other: String) =
+    if (this.isNotBlank()) {
+        "$this,$other"
+    } else {
+        other
+    }
+
+fun advance(
+    state: State,
+    program: Program,
+): Boolean {
+    val op = program.getOrNull((state.pointer / 2).toInt())
+    logger.debug { "op $op state $state" }
+    return when (op?.first) {
+        OPCODE.ADV -> {
+            state.A /= pow2(combo(state, op.second))
+            state.pointer += 2
+            true
+        }
+
+        OPCODE.BXL -> {
+            state.B = state.B.xor(op.second.toLong())
+            state.pointer += 2
+            true
+        }
+
+        OPCODE.BST -> {
+            state.B = combo(state, op.second) % 8.toLong()
+            state.pointer += 2
+            true
+        }
+
+        OPCODE.JNZ -> {
+            if (state.A == 0L) {
+                state.pointer += 2
+                true
+            } else {
+                state.pointer = op.second
+                true
+            }
+        }
+
+        OPCODE.BXC -> {
+            state.B = state.B.xor(state.C)
+            state.pointer += 2
+            true
+        }
+
+        OPCODE.OUT -> {
+            state.output = state.output join combo(state, op.second).mod(8.toLong()).toString()
+            state.pointer += 2
+            true
+        }
+
+        OPCODE.BDV -> {
+            state.B = state.A / pow2(combo(state, op.second))
+            state.pointer += 2
+            true
+        }
+
+        OPCODE.CDV -> {
+            state.C = state.A / pow2(combo(state, op.second))
+            state.pointer += 2
+            true
+        }
+
+        null -> {
+            false
+        }
+    }
+}
+
+fun String.parseProgramRaw() =
+    this
+        .removePrefix("Program: ")
+        .split(",")
+        .map { it.toInt() }
+
+fun List<Int>.toProgram() = this
+    .chunked(2)
+    .map { (o, p) ->
+        OPCODE.entries.first { it.opcode == o } to p
+    }
+
+fun String.parseProgram() =
+    this.parseProgramRaw()
+        .toProgram()
+
+suspend fun y2024day17part1(input: Input): String {
+    logger.info("year 2024 day 17 part 1")
+    val lines = input.lineFlow().toList()
+    val a = lines[0].removePrefix("Register A: ").toLong()
+    val b = lines[1].removePrefix("Register B: ").toLong()
+    val c = lines[2].removePrefix("Register C: ").toLong()
+    val program: Program =
+        lines[4].parseProgram()
+
+    val currentState =
+        State(
+            A = a,
+            B = b,
+            C = c,
+            pointer = 0,
+            output = "",
+        )
+    var i = 0
+    while (i < 100) {
+        val runNext = advance(currentState, program)
+        if (!runNext) {
+            return currentState.output
+        }
+        i++
+    }
+    return currentState.output
+}
+
+fun run(
+    program: Program,
+    a: Long,
+): List<Int> {
+    val currentState =
+        State(
+            A = a,
+            B = 0L,
+            C = 0L,
+            pointer = 0,
+            output = "",
+        )
+    var i = 0
+    while (i < 1000) {
+        val runNext = advance(currentState, program)
+        if (!runNext) {
+            return currentState.output.split(",").map { it.toInt() }
+        }
+        i++
+    }
+    return currentState.output.split(",").map { it.toInt() }
+}
+
+fun pow2(n: Long): Long =
+    if (n < 0) {
+        throw IllegalArgumentException()
+    } else if (n == 0L) {
+        1L
+    } else {
+        1L.shl(n.toInt())
+    }
+
+suspend fun y2024day17part2(input: Input): Long {
+    val lines = input.lineFlow().toList()
+    val wanted = lines[4].parseProgramRaw()
+    val program: Program = wanted.toProgram()
+
+    fun findMatch(wanted: List<Int>): List<Long> {
+        return when (wanted.size) {
+            0 -> listOf(0L)
+            else -> {
+                val smallerACandidates = findMatch(wanted.drop(1))
+
+                smallerACandidates.flatMap { smallerA ->
+                    (0..7).mapNotNull { i ->
+                        val a = smallerA * 8.toLong() + i.toLong()
+                        val output = run(program, a)
+                        logger.debug { "$smallerA, $a: $output, $wanted}" }
+                        if (wanted.isSame(output)) {
+                            logger.debug { "HIT" }
+                            a
+                        } else {
+                            null
+                        }
+                    }
+                }
+            }
+        }
+
+    }
+
+    val suitableAList = findMatch(wanted)
+    logger.debug { suitableAList }
+    return suitableAList.minOrNull() ?: error("not found")
+}
diff --git a/src/test/kotlin/cz/glubo/adventofcode/y2024/day17/Day17Test.kt b/src/test/kotlin/cz/glubo/adventofcode/y2024/day17/Day17Test.kt
new file mode 100644
index 0000000..046b8fe
--- /dev/null
+++ b/src/test/kotlin/cz/glubo/adventofcode/y2024/day17/Day17Test.kt
@@ -0,0 +1,119 @@
+package cz.glubo.adventofcode.y2024.day17
+
+import cz.glubo.adventofcode.utils.input.TestInput
+import io.kotest.core.spec.style.StringSpec
+import io.kotest.matchers.shouldBe
+import io.kotest.matchers.shouldNotBe
+
+/**
+ * https://adventofcode.com/2024/day/17
+ */
+class Day17Test :
+    StringSpec({
+
+        "a" {
+            val program =
+                listOf(
+                    OPCODE.BST to 6,
+                )
+            val state =
+                State(
+                    0.toLong(),
+                    0.toLong(),
+                    9.toLong(),
+                    0,
+                    "",
+                )
+            val nextState = advance(state, program)
+            nextState shouldNotBe false
+            state.B shouldBe 1.toLong()
+        }
+
+        "a2" {
+            val program = "1,7".parseProgram()
+
+            val state =
+                State(
+                    0.toLong(),
+                    29.toLong(),
+                    0.toLong(),
+                    0,
+                    "",
+                )
+            val nextState = advance(state, program)
+            nextState shouldNotBe false
+            state.B shouldBe 26.toLong()
+        }
+        "a3" {
+            val program = "4,0".parseProgram()
+
+            val state =
+                State(
+                    0.toLong(),
+                    2024.toLong(),
+                    43690.toLong(),
+                    0,
+                    "",
+                )
+            val nextState = advance(state, program)
+            nextState shouldNotBe false
+            state.B shouldBe 44354.toLong()
+        }
+
+        "day17 example 2 part 1 matches" {
+            y2024day17part1(
+                TestInput(
+                    """
+                    Register A: 10
+                    Register B: 0
+                    Register C: 0
+
+                    Program: 5,0,5,1,5,4
+                    """.trimIndent(),
+                ),
+            ) shouldBe "0,1,2"
+        }
+
+        "day17 example 3 part 1 matches" {
+            y2024day17part1(
+                TestInput(
+                    """
+                    Register A: 2024
+                    Register B: 0
+                    Register C: 0
+
+                    Program: 0,1,5,4,3,0
+                    """.trimIndent(),
+                ),
+            ) shouldBe "4,2,5,6,7,7,7,7,3,1,0"
+        }
+
+        "day17 example part 1 matches" {
+            y2024day17part1(
+                TestInput(
+                    """
+                    Register A: 729
+                    Register B: 0
+                    Register C: 0
+
+                    Program: 0,1,5,4,3,0
+                    """.trimIndent(),
+                ),
+            ) shouldBe "4,6,3,5,6,3,5,2,1,0"
+        }
+
+        "day17 example part 2 matches" {
+            y2024day17part2(
+                TestInput(
+                    """
+                        Register A: 2024
+                        Register B: 0
+                        Register C: 0
+
+                        Program: 0,3,5,4,3,0
+                    """.trimIndent(),
+                ),
+            ) shouldBe 117440.toLong()
+        }
+
+    })
diff --git a/versions.properties b/versions.properties
index 3560e39..be6431d 100644
--- a/versions.properties
+++ b/versions.properties
@@ -7,6 +7,9 @@
 #### suppress inspection "SpellCheckingInspection" for whole file
 #### suppress inspection "UnusedProperty" for whole file
 
+plugin.com.adarshr.test-logger=4.0.0
+
+
 plugin.org.jmailen.kotlinter=4.5.0
 
 ## unused
@@ -35,8 +38,19 @@ version.kotest=5.9.1
 
 version.kotlinx.coroutines=1.9.0
 
-version.kotlin=2.0.20
+version.kotlin=2.0.21
+## # available=2.0.21-RC
+## # available=2.0.21
+## # available=2.1.0-Beta1
+## # available=2.1.0-Beta2
+## # available=2.1.0-RC
+## # available=2.1.0-RC2
+## # available=2.1.0
 
 version.info.picocli..picocli=4.7.6
 
-plugin.com.github.johnrengelman.shadow=8.1.1
+plugin.com.gradleup.shadow=8.3.5
+##             # available=9.0.0-beta1
+##             # available=9.0.0-beta2
+##             # available=9.0.0-beta3
+##             # available=9.0.0-beta4