diff --git a/product-of-array-except-self/aa601.py b/product-of-array-except-self/aa601.py
new file mode 100644
index 000000000..cfd7ab4d9
--- /dev/null
+++ b/product-of-array-except-self/aa601.py
@@ -0,0 +1,17 @@
+#시간복잡도: O(n), 공간복잡도 : O(n)
+
+class Solution:
+	def productExceptSelf(self, nums: list[int]) -> list[int] :
+		a = [1] * len(nums)
+		for n in range(len(nums) - 1) :
+			a[n + 1] = a[n] * nums[n]
+
+		b = [1] * len(nums)
+		for n in range(len(nums) - 1, 0, -1) :
+			b[n - 1] = b[n] * nums[n]
+
+		c = [1] * len(nums)
+		for n in range(len(nums)) :
+			c[n] = a[n] * b[n]
+		return c
+
diff --git a/reverse-bits/aa601.py b/reverse-bits/aa601.py
new file mode 100644
index 000000000..adb619f25
--- /dev/null
+++ b/reverse-bits/aa601.py
@@ -0,0 +1,10 @@
+#시간복잡도 : O(1), 공간복잡도 : O(1)
+
+class Solution:
+	def reverseBits(self, n: int) -> int:
+		ret = 0
+		for i in range(32) :
+			ret = (ret << 1 | (n & 1))
+			n >>= 1
+		return (ret)
+
diff --git a/two-sum/aa601.py b/two-sum/aa601.py
new file mode 100644
index 000000000..d5e9875d6
--- /dev/null
+++ b/two-sum/aa601.py
@@ -0,0 +1,9 @@
+#시간복잡도 : O(n^2), 공간복잡도 : O(1)
+
+class Solution:
+	def twoSum(self, nums: list[int], target: int) -> list[int]:
+		for i in range(len(nums) - 1):
+			for k in range(i + 1, len(nums)):
+				if (nums[i] + nums[k] == target):
+					return ([i, k])
+