diff --git "a/leetcode3/\354\265\234\354\233\220\354\244\200/3719. Longest Balanced Subarray I.py" "b/leetcode3/\354\265\234\354\233\220\354\244\200/3719. Longest Balanced Subarray I.py"
new file mode 100644
index 00000000..a6ef80d7
--- /dev/null
+++ "b/leetcode3/\354\265\234\354\233\220\354\244\200/3719. Longest Balanced Subarray I.py"	
@@ -0,0 +1,21 @@
+class Solution:
+    def longestBalanced(self, nums: list[int]) -> int:
+        n = len(nums)
+        ans = 0
+
+        for i in range(n):
+            even = set()
+            odd = set()
+
+            for j in range(i, n):
+                num = nums[j]
+
+                if num % 2 == 0:
+                    even.add(num)
+                else:
+                    odd.add(num)
+
+                if len(even) == len(odd):
+                    ans = max(ans, j - i + 1)
+
+        return ans