diff --git a/contest/src/main/java/com/github/contest/binaryTree/BinaryTreeLeetcode.kt b/contest/src/main/java/com/github/contest/binaryTree/BinaryTreeLeetcode.kt
index 84afd39..0dd4ccc 100644
--- a/contest/src/main/java/com/github/contest/binaryTree/BinaryTreeLeetcode.kt
+++ b/contest/src/main/java/com/github/contest/binaryTree/BinaryTreeLeetcode.kt
@@ -244,3 +244,19 @@ private data class TreeNodeRelative(
     val sumLevels: List<Int>,
     val parentToChildrenSum: Map<TreeNode, Int>
 )
+
+/**
+ * 617. Merge Two Binary Trees
+ */
+
+fun mergeTrees(root1: TreeNode?, root2: TreeNode?): TreeNode? {
+    if (root1 == null && root2 == null) return null
+    root1 ?: return root2
+    root2 ?: return root1
+
+    val newRoot = TreeNode(root1.`val` + root2.`val`)
+    newRoot.left = mergeTrees(root1?.left, root2?.left)
+    newRoot?.right = mergeTrees(root1?.right, root2?.right)
+
+    return newRoot
+}
diff --git a/contest/src/main/java/com/github/contest/binaryTree/BinaryTreeProdVariant.kt b/contest/src/main/java/com/github/contest/binaryTree/BinaryTreeProdVariant.kt
index 522258b..7df2394 100644
--- a/contest/src/main/java/com/github/contest/binaryTree/BinaryTreeProdVariant.kt
+++ b/contest/src/main/java/com/github/contest/binaryTree/BinaryTreeProdVariant.kt
@@ -61,4 +61,20 @@ fun isCousinsProdVariant(root: TreeNode?, x: Int, y: Int): Boolean {
     }
 
     return false
+}
+
+/**
+ * 617. Merge Two Binary Trees
+ */
+
+fun mergeTreesProdVariant(root1: TreeNode?, root2: TreeNode?): TreeNode? = when {
+    root1 == null && root2 == null -> null
+    root1 == null -> root2
+    root2 == null -> root1
+    else -> {
+        val newRoot = TreeNode(root1.`val` + root2.`val`)
+        newRoot.left = mergeTreesProdVariant(root1?.left, root2.left)
+        newRoot.right = mergeTreesProdVariant(root1?.right, root2?.right)
+        newRoot
+    }
 }
\ No newline at end of file
diff --git a/contest/src/main/java/com/github/contest/hashTable/HashTableLeetcode.kt b/contest/src/main/java/com/github/contest/hashTable/HashTableLeetcode.kt
index 8568666..4d076f3 100644
--- a/contest/src/main/java/com/github/contest/hashTable/HashTableLeetcode.kt
+++ b/contest/src/main/java/com/github/contest/hashTable/HashTableLeetcode.kt
@@ -662,3 +662,26 @@ fun isVowel(char: Char) = when {
     char in "aeiou" -> true
     else -> false
 }
+
+/**
+ *  3005. Count Elements With Maximum Frequency
+ */
+
+fun maxFrequencyElements(nums: IntArray): Int {
+    if (nums.hasSingle()) return 1
+
+    val freq = nums.toList().groupingBy { it }.eachCount()
+    var max = 0
+    var res = 0
+
+    for ((_, value) in freq) max = maxOf(max, value)
+
+    for ((_, value) in freq) {
+        if (value == max) res += value
+    }
+
+    return res
+
+}
+
+