diff --git a/1286-constrained-subsequence-sum/1286-constrained-subsequence-sum.py b/1286-constrained-subsequence-sum/1286-constrained-subsequence-sum.py
new file mode 100644
index 0000000..6f2278b
--- /dev/null
+++ b/1286-constrained-subsequence-sum/1286-constrained-subsequence-sum.py
@@ -0,0 +1,20 @@
+class Solution:
+  def constrainedSubsetSum(self, nums: List[int], k: int) -> int:
+    # dp[i] := max sum of non-empty subsequence in nums[0..i]
+    dp = [0] * len(nums)
+    # dq stores dp[i - k], dp[i - k + 1], ..., dp[i - 1] whose values are > 0
+    # in decreasing order.
+    dq = collections.deque()
+
+    for i, num in enumerate(nums):
+      if dq:
+        dp[i] = max(dq[0], 0) + num
+      else:
+        dp[i] = num
+      while dq and dq[-1] < dp[i]:
+        dq.pop()
+      dq.append(dp[i])
+      if i >= k and dp[i - k] == dq[0]:
+        dq.popleft()
+
+    return max(dp)