diff --git a/sik9252/NumberOf1Bits.js b/sik9252/NumberOf1Bits.js
new file mode 100644
index 0000000..c3abdda
--- /dev/null
+++ b/sik9252/NumberOf1Bits.js
@@ -0,0 +1,10 @@
+var hammingWeight = function (n) {
+  let count = 0;
+
+  while (n !== 0) {
+    n = n & (n - 1);
+    count++;
+  }
+
+  return count;
+};
diff --git a/sik9252/SameTree.js b/sik9252/SameTree.js
new file mode 100644
index 0000000..c1a799e
--- /dev/null
+++ b/sik9252/SameTree.js
@@ -0,0 +1,7 @@
+var isSameTree = function (p, q) {
+  if (!p && !q) return true; // 둘 다 없으면(null)
+  if (!p || !q) return false; // 둘 중 하나만 없으면(null)
+  if (p.val !== q.val) return false; // 값이 다르면
+
+  return isSameTree(p.left, q.left) && isSameTree(p.right, q.right); // 서브트리 확인
+};