diff --git a/build.gradle.kts b/build.gradle.kts
index b5c3de5..98d96f2 100644
--- a/build.gradle.kts
+++ b/build.gradle.kts
@@ -34,7 +34,7 @@ dependencies {
     implementation("io.micronaut.serde:micronaut-serde-jackson")
     implementation("org.jetbrains.kotlin:kotlin-reflect:${kotlinVersion}")
     implementation("org.jetbrains.kotlin:kotlin-stdlib-jdk8:${kotlinVersion}")
-    implementation("de.linkel.aoc:aoc-utils:1.0.0")
+    implementation("de.linkel.aoc:aoc-utils:1.0.1")
     runtimeOnly("ch.qos.logback:logback-classic")
     runtimeOnly("com.fasterxml.jackson.module:jackson-module-kotlin")
     testImplementation("org.assertj:assertj-core:3.24.2")
diff --git a/src/main/kotlin/de/linkel/aoc/Day03.kt b/src/main/kotlin/de/linkel/aoc/Day03.kt
index 09b83f9..557abdc 100644
--- a/src/main/kotlin/de/linkel/aoc/Day03.kt
+++ b/src/main/kotlin/de/linkel/aoc/Day03.kt
@@ -2,6 +2,10 @@ package de.linkel.aoc
 
 import de.linkel.aoc.base.AbstractLinesAdventDay
 import de.linkel.aoc.base.QuizPart
+import de.linkel.aoc.utils.append
+import de.linkel.aoc.utils.extend
+import de.linkel.aoc.utils.intersects
+import de.linkel.aoc.utils.prepend
 import jakarta.inject.Singleton
 
 @Singleton
@@ -9,6 +13,41 @@ class Day03: AbstractLinesAdventDay<Int>() {
     override val day = 3
 
     override fun process(part: QuizPart, lines: Sequence<String>): Int {
-        return 0
+        val digitPattern = Regex("[0-9]+")
+        val symbolPattern = Regex("[^0-9.]")
+        val asteriskPattern = Regex("\\*")
+        val result = lines
+            .prepend("")
+            .append("")
+            .windowed(3)
+            .map { win ->
+                val allNumbersPerLine = win.map { digitPattern.findAll(it) }.map { it.toList() }
+                val allSymbols = win.flatMap { symbolPattern.findAll(it) }.toList()
+                val partNumbers = allNumbersPerLine[1]
+                    .filter { match ->
+                        val checkrange = match.range.extend(front = 1, back = 1)
+                        allSymbols
+                            .any { it.range.intersects(checkrange) }
+                    }
+                    .sumOf { it.value.toInt() }
+                val allNumbers = allNumbersPerLine.flatten()
+                val gears = asteriskPattern.findAll(win[1])
+                    .map { match ->
+                        val checkrange = match.range.extend(front = 1, back = 1)
+                        allNumbers
+                            .filter { it.range.intersects(checkrange) }
+                            .map { it.value.toInt() }
+                    }
+                    .filter { it.size == 2 }
+                    .map { it[0] * it[1] }
+                    .sum()
+                Pair(partNumbers, gears)
+            }
+            .fold(Pair(0,0)) {
+                sum, line ->
+                Pair(sum.first + line.first, sum.second + line.second)
+            }
+        return if (part == QuizPart.A) result.first
+            else result.second
     }
 }
diff --git a/src/test/kotlin/de/linkel/aoc/Day03Test.kt b/src/test/kotlin/de/linkel/aoc/Day03Test.kt
index 333efd8..d976714 100644
--- a/src/test/kotlin/de/linkel/aoc/Day03Test.kt
+++ b/src/test/kotlin/de/linkel/aoc/Day03Test.kt
@@ -2,12 +2,22 @@ package de.linkel.aoc
 
 class Day03Test: AbstractDayTest<Int>() {
     override val exampleA = """
+467..114..
+...*......
+..35..633.
+......#...
+617*......
+.....+.58.
+..592.....
+......755.
+...${'$'}.*....
+.664.598..
         """.trimIndent()
-    override val exampleSolutionA = 0
-    override val solutionA = 0
+    override val exampleSolutionA = 4361
+    override val solutionA = 559667
 
-    override val exampleSolutionB = 0
-    override val solutionB = 0
+    override val exampleSolutionB = 467835
+    override val solutionB = 86841457
 
     override val implementation = Day03()
 }