diff --git a/src/main/java/com/cool/ling_cha_mount/sliding_windows/Num2841.java b/src/main/java/com/cool/ling_cha_mount/sliding_windows/Num2841.java
new file mode 100644
index 0000000..76fbc3d
--- /dev/null
+++ b/src/main/java/com/cool/ling_cha_mount/sliding_windows/Num2841.java
@@ -0,0 +1,52 @@
+package com.cool.ling_cha_mount.sliding_windows;
+
+import java.util.HashMap;
+import java.util.List;
+import java.util.Map;
+
+/**
+ * Created with IntelliJ IDEA.
+ *
+ * @Author: Cool
+ * @Date: 2024/10/09/17:24
+ * @Description:
+ */
+public class Num2841 {
+
+    public long maxSum(List<Integer> nums, int m, int k) {
+        Map<Integer,Integer> map=new HashMap<>();
+        long sum=0;
+        for(int i=0;i<k;i++){
+            Integer integer =nums.get(i);
+            if(!map.containsKey(integer)){
+                map.put(integer,1);
+            }else{
+                map.put(integer,map.get(integer)+1);
+            }
+            sum+= integer;
+        }
+        long res=0;
+        if(map.size()>=m){
+            res=sum;
+        }
+        for(int i=k;i<nums.size();i++){
+            Integer left=nums.get(i-k);
+            Integer right=nums.get(i);
+            map.put(left,map.get(left)-1);
+            if(map.get(left).equals(0)){
+                map.remove(left);
+            }
+            if(!map.containsKey(right)){
+                map.put(right,1);
+            }else{
+                map.put(right,map.get(right)+1);
+            }
+            sum-=left;
+            sum+=right;
+            if(map.size()>=m){
+                res=Math.max(res,sum);
+            }
+        }
+        return res;
+    }
+}