diff --git a/src/main/java/com/dota/bit/_2680/Solution.java b/src/main/java/com/dota/bit/_2680/Solution.java
new file mode 100644
index 0000000..8ffd4ad
--- /dev/null
+++ b/src/main/java/com/dota/bit/_2680/Solution.java
@@ -0,0 +1,19 @@
+package com.dota.bit._2680;
+
+class Solution {
+    public long maximumOr(int[] nums, int k) {
+        long max = 0;
+        long[] suf = new long[nums.length + 1];
+        long pre = 0;
+        for (int i = nums.length-1; i >=0 ; i--) {
+            suf[i] = nums[i] | suf[i+1];
+        }
+
+        for (int i = 0; i < nums.length; i++) {
+            max = Math.max(max, pre | ((long) nums[i] <<k) | suf[i+1]);
+            pre |= nums[i];
+        }
+
+        return max;
+    }
+}
\ No newline at end of file
diff --git a/src/main/java/com/dota/slidingWindow/_3439/Solution.java b/src/main/java/com/dota/slidingWindow/_3439/Solution.java
new file mode 100644
index 0000000..7424e48
--- /dev/null
+++ b/src/main/java/com/dota/slidingWindow/_3439/Solution.java
@@ -0,0 +1,39 @@
+package com.dota.slidingWindow._3439;
+
+import java.util.ArrayList;
+
+class Solution {
+	public int maxFreeTime(int eventTime, int k, int[] startTime, int[] endTime) {
+		int max = 0;
+    var list = new ArrayList<Integer>();
+		if (startTime[0] !=0) {
+			list.add(startTime[0]);
+		}
+
+		int n = startTime.length;
+
+		for (int i = 1; i < n; i++) {
+			int t = startTime[i] - endTime[i - 1];
+				list.add(t);
+		}
+
+		if (endTime[n-1] !=eventTime) {
+      list.add(eventTime - endTime[n-1]);
+		}
+
+		int sum=0;
+		k++;
+		for (int i = 0; i < k && i<list.size(); i++) {
+			sum += list.get(i);
+		}
+		max = sum;
+		int l=0,r=k;
+		while(r<list.size()) {
+				sum += list.get(r++);
+				sum -= list.get(l++);
+				max = Math.max(max, sum);
+		}
+
+		return max;
+	}
+}
\ No newline at end of file