diff --git a/src/Utils.kt b/src/Utils.kt
index 14568d2..49e1893 100644
--- a/src/Utils.kt
+++ b/src/Utils.kt
@@ -2,6 +2,13 @@ import java.io.File
 import java.math.BigInteger
 import java.security.MessageDigest
 
+fun Int.gcd(b: Int): Int = if (b == 0) this else b.gcd(this % b)
+fun Long.gcd(b: Long): Long = if (b == 0L) this else b.gcd(this % b)
+fun Int.lcm(b: Int): Int = this / gcd(b) * b
+fun Long.lcm(b: Long): Long = this / gcd(b) * b
+fun Iterable<Int>.lcm(): Int = reduce(Int::lcm)
+fun Iterable<Long>.lcm(): Long = reduce(Long::lcm)
+
 /**
  * Reads lines from the given input txt file.
  */
diff --git a/src/aoc2023/Day08.kt b/src/aoc2023/Day08.kt
index 633f5fc..6bba147 100644
--- a/src/aoc2023/Day08.kt
+++ b/src/aoc2023/Day08.kt
@@ -1,5 +1,6 @@
 package aoc2023
 
+import lcm
 import println
 import readInput
 
@@ -95,36 +96,37 @@ XXX = (XXX, XXX)
             } while (!loc.endsWith("Z"))
             ggts.add(steps)
         }
-        val primes = ArrayList<Int>()
-        val factors = HashSet<Int>()
-        var prime = 2
-        primes.add(2)
-        do {
-            val newGgts = HashSet<Int>()
-            for (f in ggts) {
-                if (prime * 2 - 1 > f) {
-                    factors.add(f)
-                } else {
-                    if (f % prime == 0) {
-                        newGgts.add(f / prime)
-                        factors.add(prime)
-                    } else {
-                        newGgts.add(f)
-                    }
-                }
-            }
-            ggts = newGgts
-            if (prime == 2) {
-                prime = 3
-            } else {
-                do {
-                    prime += 2
-                } while (primes.any { (prime % it) == 0 })
-            }
-            primes.add(prime)
-        } while (ggts.isNotEmpty())
-
-        return factors.map { it.toLong() }.reduce(Long::times)
+        return ggts.map(Int::toLong).lcm()
+//        val primes = ArrayList<Int>()
+//        val factors = HashSet<Int>()
+//        var prime = 2
+//        primes.add(2)
+//        do {
+//            val newGgts = HashSet<Int>()
+//            for (f in ggts) {
+//                if (prime * 2 - 1 > f) {
+//                    factors.add(f)
+//                } else {
+//                    if (f % prime == 0) {
+//                        newGgts.add(f / prime)
+//                        factors.add(prime)
+//                    } else {
+//                        newGgts.add(f)
+//                    }
+//                }
+//            }
+//            ggts = newGgts
+//            if (prime == 2) {
+//                prime = 3
+//            } else {
+//                do {
+//                    prime += 2
+//                } while (primes.any { (prime % it) == 0 })
+//            }
+//            primes.add(prime)
+//        } while (ggts.isNotEmpty())
+//
+//        return factors.map { it.toLong() }.reduce(Long::times)
     }
 
     // test if implementation meets criteria from the description, like: