diff --git a/Sprint-1/fix/median.js b/Sprint-1/fix/median.js
index b22590bc6..d55963dd9 100644
--- a/Sprint-1/fix/median.js
+++ b/Sprint-1/fix/median.js
@@ -6,9 +6,22 @@
 // or 'list' has mixed values (the function is expected to sort only numbers).
 
 function calculateMedian(list) {
-  const middleIndex = Math.floor(list.length / 2);
-  const median = list.splice(middleIndex, 1)[0];
-  return median;
+  if (!Array.isArray(list)) {
+    return null;
+  }
+  const numbersOnly = list.filter((item) => typeof item === "number");
+  if (numbersOnly.length === 0) {
+    return null;
+  }
+  const sortedNumbers = [...numbersOnly].sort((a, b) => a - b);
+
+  const len = sortedNumbers.length;
+  const middleIndex = Math.floor(len / 2);
+  if (len % 2 !== 0) {
+    return sortedNumbers[middleIndex];
+  } else {
+    return (sortedNumbers[middleIndex - 1] + sortedNumbers[middleIndex]) / 2;
+  }
 }
 
 module.exports = calculateMedian;
diff --git a/Sprint-1/implement/dedupe.js b/Sprint-1/implement/dedupe.js
index 781e8718a..6bd57109d 100644
--- a/Sprint-1/implement/dedupe.js
+++ b/Sprint-1/implement/dedupe.js
@@ -1 +1,8 @@
-function dedupe() {}
+function dedupe(list) {
+  if (!Array.isArray(list)) {
+    return list;
+  }
+  return [...new Set(list)];
+}
+
+module.exports = dedupe;
diff --git a/Sprint-1/implement/max.js b/Sprint-1/implement/max.js
index 6dd76378e..a0c6b882c 100644
--- a/Sprint-1/implement/max.js
+++ b/Sprint-1/implement/max.js
@@ -1,4 +1,9 @@
 function findMax(elements) {
+  const numbersOnly = elements.filter((item) => typeof item === "number");
+  if (numbersOnly.length === 0) {
+    return -Infinity;
+  }
+  return Math.max(...numbersOnly);
 }
 
 module.exports = findMax;
diff --git a/Sprint-1/implement/sum.js b/Sprint-1/implement/sum.js
index 9062aafe3..57051a30d 100644
--- a/Sprint-1/implement/sum.js
+++ b/Sprint-1/implement/sum.js
@@ -1,4 +1,6 @@
-function sum(elements) {
+function sum(numbers) {
+  const numbersOnly = numbers.filter((item) => typeof item === "number");
+  return numbersOnly.reduce((total, current) => total + current, 0);
 }
 
 module.exports = sum;
diff --git a/Sprint-1/package-lock.json b/Sprint-1/package-lock.json
index 83e427d0b..b52480af5 100644
--- a/Sprint-1/package-lock.json
+++ b/Sprint-1/package-lock.json
@@ -56,6 +56,7 @@
       "integrity": "sha512-Oixnb+DzmRT30qu9d3tJSQkxuygWm32DFykT4bRoORPa9hZ/L4KhVB/XiRm6KG+roIEM7DBQlmg27kw2HZkdZg==",
       "dev": true,
       "license": "MIT",
+      "peer": true,
       "dependencies": {
         "@ampproject/remapping": "^2.2.0",
         "@babel/code-frame": "^7.25.7",
@@ -1368,6 +1369,7 @@
         }
       ],
       "license": "MIT",
+      "peer": true,
       "dependencies": {
         "caniuse-lite": "^1.0.30001663",
         "electron-to-chromium": "^1.5.28",
diff --git a/Sprint-1/refactor/includes.js b/Sprint-1/refactor/includes.js
index 29dad81f0..a1a53ff8f 100644
--- a/Sprint-1/refactor/includes.js
+++ b/Sprint-1/refactor/includes.js
@@ -1,8 +1,7 @@
 // Refactor the implementation of includes to use a for...of loop
 
 function includes(list, target) {
-  for (let index = 0; index < list.length; index++) {
-    const element = list[index];
+  for (const element of list) {
     if (element === target) {
       return true;
     }
@@ -10,4 +9,4 @@ function includes(list, target) {
   return false;
 }
 
-module.exports = includes;
+module.exports = includes;
\ No newline at end of file
diff --git a/Sprint-1/stretch/aoc-2018-day1/solution.js b/Sprint-1/stretch/aoc-2018-day1/solution.js
index e69de29bb..8e923e3cd 100644
--- a/Sprint-1/stretch/aoc-2018-day1/solution.js
+++ b/Sprint-1/stretch/aoc-2018-day1/solution.js
@@ -0,0 +1,7 @@
+function calibrate(input) {
+  return input.reduce((total, change) => {
+    return total + parseInt(change, 10);
+  }, 0);
+}
+
+module.exports = calibrate;
\ No newline at end of file