diff --git a/sik9252/ClimbingStairs.js b/sik9252/ClimbingStairs.js
new file mode 100644
index 0000000..570dc66
--- /dev/null
+++ b/sik9252/ClimbingStairs.js
@@ -0,0 +1,15 @@
+/**
+ * @param {number} n
+ * @return {number}
+ */
+var climbStairs = function (n) {
+  const dp = new Array(n + 1);
+  dp[1] = 1;
+  dp[2] = 2;
+
+  for (let i = 3; i <= n; i++) {
+    dp[i] = dp[i - 1] + dp[i - 2];
+  }
+
+  return dp[n];
+};
diff --git a/sik9252/LongestPalindrome.js b/sik9252/LongestPalindrome.js
new file mode 100644
index 0000000..eab6c7e
--- /dev/null
+++ b/sik9252/LongestPalindrome.js
@@ -0,0 +1,23 @@
+/**
+ * @param {string} s
+ * @return {number}
+ */
+var longestPalindrome = function (s) {
+  const set = new Set();
+  let length = 0;
+
+  for (const char of s) {
+    if (set.has(char)) {
+      set.delete(char);
+      length += 2;
+    } else {
+      set.add(char);
+    }
+  }
+
+  if (set.size > 0) {
+    length += 1;
+  }
+
+  return length;
+};