diff --git a/package.json b/package.json
index b2e3f8c..71b6194 100644
--- a/package.json
+++ b/package.json
@@ -18,6 +18,7 @@
     "typescript": "^5.3.2"
   },
   "dependencies": {
-    "lodash": "^4.17.21"
+    "lodash": "^4.17.21",
+    "parjs": "^0.16.1"
   }
 }
diff --git a/src/day_four.ts b/src/day_four.ts
index 64905d3..b84a9cc 100644
--- a/src/day_four.ts
+++ b/src/day_four.ts
@@ -1,6 +1,18 @@
 import fs from "fs";
-import {Engine} from "./day_three";
-import {forEach} from "lodash";
+import {whitespace, int, string} from "parjs";
+import {between, manySepBy, then} from "parjs/combinators";
+
+const cardIdParser = int()
+	.pipe(between(whitespace()))
+	.pipe(between(string('Card'), string(': ')));
+
+const numbersParser = int()
+	.pipe(between(whitespace()))
+	.pipe(manySepBy(whitespace()));
+
+const winningNumberParser = numbersParser
+	.pipe(between(cardIdParser, string('|')))
+	.pipe(then(numbersParser));
 
 export class Scratchcard {
 	private readonly numbers: number[];
@@ -8,11 +20,13 @@ export class Scratchcard {
 	private children: Scratchcard[] = [];
 
 	constructor(input: string) {
-		const [_, withoutId] = input.split(':');
-		const [winning, ourNumbers] = withoutId.split('|');
+		const [
+			winningNumbers,
+			numbers
+		] = winningNumberParser.parse(input).value;
 
-		this.winningNumbers = this.parseNumberList(winning);
-		this.numbers = this.parseNumberList(ourNumbers);
+		this.winningNumbers = winningNumbers;
+		this.numbers = numbers;
 	}
 
 	private parseNumberList(input: string): number[] {
diff --git a/yarn.lock b/yarn.lock
index c206610..f50d58c 100644
--- a/yarn.lock
+++ b/yarn.lock
@@ -901,6 +901,13 @@ chalk@^4.0.0:
     ansi-styles "^4.1.0"
     supports-color "^7.1.0"
 
+char-info@^0.3.2:
+  version "0.3.2"
+  resolved "https://registry.yarnpkg.com/char-info/-/char-info-0.3.2.tgz#d4c4d034245c864d1ab17152cd31746b3bd4f0d0"
+  integrity sha512-6P6KW8crZx+N857wZalB4FreR+PhheSLmAk22c8zbQsFhsDxZP1aTDfmOjrzddgp1IBOl53b0Z8kDQrwh4B//A==
+  dependencies:
+    node-interval-tree "^1.3.3"
+
 char-regex@^1.0.2:
   version "1.0.2"
   resolved "https://registry.yarnpkg.com/char-regex/-/char-regex-1.0.2.tgz#d744358226217f981ed58f479b1d6bcc29545dcf"
@@ -1819,6 +1826,13 @@ node-int64@^0.4.0:
   resolved "https://registry.yarnpkg.com/node-int64/-/node-int64-0.4.0.tgz#87a9065cdb355d3182d8f94ce11188b825c68a3b"
   integrity sha512-O5lz91xSOeoXP6DulyHfllpq+Eg00MWitZIbtPfoSEvqIHdl5gfcY6hYzDWnj0qD5tz52PI08u9qUvSVeUBeHw==
 
+node-interval-tree@^1.3.3:
+  version "1.3.3"
+  resolved "https://registry.yarnpkg.com/node-interval-tree/-/node-interval-tree-1.3.3.tgz#15ffb904cde08270214acace8dc7653e89ae32b7"
+  integrity sha512-K9vk96HdTK5fEipJwxSvIIqwTqr4e3HRJeJrNxBSeVMNSC/JWARRaX7etOLOuTmrRMeOI/K5TCJu3aWIwZiNTw==
+  dependencies:
+    shallowequal "^1.0.2"
+
 node-releases@^2.0.13:
   version "2.0.14"
   resolved "https://registry.yarnpkg.com/node-releases/-/node-releases-2.0.14.tgz#2ffb053bceb8b2be8495ece1ab6ce600c4461b0b"
@@ -1876,6 +1890,14 @@ p-try@^2.0.0:
   resolved "https://registry.yarnpkg.com/p-try/-/p-try-2.2.0.tgz#cb2868540e313d61de58fafbe35ce9004d5540e6"
   integrity sha512-R4nPAVTAU0B9D35/Gk3uJf/7XYbQcyohSKdvAxIRSNghFl4e71hVoGnBNQz9cWaXxO2I10KTC+3jMdvvoKw6dQ==
 
+parjs@^0.16.1:
+  version "0.16.1"
+  resolved "https://registry.yarnpkg.com/parjs/-/parjs-0.16.1.tgz#cce6c1d5cdfc90e2ff8234125af2e3410081d7f2"
+  integrity sha512-/r+iT+Erol+S33m2NcmbDigCeazTkNKZLBzNJFclqrTOMqQUr1IpM8bL7hc7Ai7GrLpbESLlgP6NYoPfO1HFAA==
+  dependencies:
+    char-info "^0.3.2"
+    lodash "^4.17.21"
+
 parse-json@^5.2.0:
   version "5.2.0"
   resolved "https://registry.yarnpkg.com/parse-json/-/parse-json-5.2.0.tgz#c76fc66dee54231c962b22bcc8a72cf2f99753cd"
@@ -1998,6 +2020,11 @@ semver@^7.5.3, semver@^7.5.4:
   dependencies:
     lru-cache "^6.0.0"
 
+shallowequal@^1.0.2:
+  version "1.1.0"
+  resolved "https://registry.yarnpkg.com/shallowequal/-/shallowequal-1.1.0.tgz#188d521de95b9087404fd4dcb68b13df0ae4e7f8"
+  integrity sha512-y0m1JoUZSlPAjXVtPPW70aZWfIL/dSP7AFkRnniLCrK/8MDKog3TySTBmckD+RObVxH0v4Tox67+F14PdED2oQ==
+
 shebang-command@^2.0.0:
   version "2.0.0"
   resolved "https://registry.yarnpkg.com/shebang-command/-/shebang-command-2.0.0.tgz#ccd0af4f8835fbdc265b82461aaf0c36663f34ea"