diff --git a/bangdori/33.js b/bangdori/33.js
new file mode 100644
index 0000000..a0cfafb
--- /dev/null
+++ b/bangdori/33.js
@@ -0,0 +1,30 @@
+/**
+ * @param {number[]} nums
+ * @param {number} target
+ * @return {number}
+ */
+var search = function (nums, target) {
+  let left = 0,
+    right = nums.length - 1;
+
+  while (left <= right) {
+    const mid = Math.floor((left + right) / 2);
+    if (nums[mid] === target) return mid;
+
+    if (nums[left] <= nums[mid]) {
+      if (nums[left] <= target && target < nums[mid]) {
+        right = mid - 1;
+      } else {
+        left = mid + 1;
+      }
+    } else {
+      if (nums[mid] < target && target <= nums[right]) {
+        left = mid + 1;
+      } else {
+        right = mid - 1;
+      }
+    }
+  }
+
+  return -1;
+};