diff --git a/bangdori/4.js b/bangdori/4.js
new file mode 100644
index 0000000..782e2fa
--- /dev/null
+++ b/bangdori/4.js
@@ -0,0 +1,32 @@
+/**
+ * @param {number[]} nums1
+ * @param {number[]} nums2
+ * @return {number}
+ */
+var findMedianSortedArrays = function (nums1, nums2) {
+  const totalSize = nums1.length + nums2.length;
+  const isOdd = totalSize % 2 === 1;
+  const answer = [];
+
+  let i1 = 0;
+  let i2 = 0;
+  for (let count = 1; count <= totalSize; count++) {
+    if (answer.length === 2) continue;
+
+    if (i1 >= nums1.length || (i2 < nums2.length && nums2[i2] <= nums1[i1])) {
+      i2++;
+
+      if (count >= totalSize / 2) {
+        answer.push(nums2[i2 - 1]);
+      }
+    } else {
+      i1++;
+
+      if (count >= totalSize / 2) {
+        answer.push(nums1[i1 - 1]);
+      }
+    }
+  }
+
+  return isOdd ? answer[0] : (answer[0] + answer[1]) / 2;
+};