diff --git a/0002-add-two-numbers/0002-add-two-numbers.cs b/0002-add-two-numbers/0002-add-two-numbers.cs
new file mode 100644
index 0000000..7bebb4c
--- /dev/null
+++ b/0002-add-two-numbers/0002-add-two-numbers.cs
@@ -0,0 +1,34 @@
+/**
+ * Definition for singly-linked list.
+ * public class ListNode {
+ *     public int val;
+ *     public ListNode next;
+ *     public ListNode(int x) { val = x; }
+ * }
+ */
+public class Solution {
+    public ListNode AddTwoNumbers(ListNode l1, ListNode l2) {
+        ListNode dummy = new ListNode(0);
+        ListNode current = dummy;
+        int carry = 0;
+        
+        while (l1 != null || l2 != null || carry != 0) {
+            int sum = carry;
+            if (l1 != null) {
+                sum += l1.val;
+                l1 = l1.next;
+            }
+            if (l2 != null) {
+                sum += l2.val;
+                l2 = l2.next;
+            }
+            
+            carry = sum / 10;
+            sum = sum % 10;
+            current.next = new ListNode(sum);
+            current = current.next;
+        }
+        
+        return dummy.next;
+    }
+}
\ No newline at end of file
diff --git a/0002-add-two-numbers/0002-add-two-numbers.java b/0002-add-two-numbers/0002-add-two-numbers.java
new file mode 100644
index 0000000..ae864e0
--- /dev/null
+++ b/0002-add-two-numbers/0002-add-two-numbers.java
@@ -0,0 +1,36 @@
+/**
+ * Definition for singly-linked list.
+ * public class ListNode {
+ *     int val;
+ *     ListNode next;
+ *     ListNode() {}
+ *     ListNode(int val) { this.val = val; }
+ *     ListNode(int val, ListNode next) { this.val = val; this.next = next; }
+ * }
+ */
+class Solution {
+    public ListNode addTwoNumbers(ListNode l1, ListNode l2) {
+        ListNode dummy = new ListNode(0);
+        ListNode current = dummy;
+        int carry = 0;
+        
+        while (l1 != null || l2 != null || carry != 0) {
+            int sum = carry;
+            if (l1 != null) {
+                sum += l1.val;
+                l1 = l1.next;
+            }
+            if (l2 != null) {
+                sum += l2.val;
+                l2 = l2.next;
+            }
+            
+            carry = sum / 10;
+            sum = sum % 10;
+            current.next = new ListNode(sum);
+            current = current.next;
+        }
+        
+        return dummy.next;
+    }
+}
\ No newline at end of file
diff --git a/0002-add-two-numbers/0002-add-two-numbers.js b/0002-add-two-numbers/0002-add-two-numbers.js
new file mode 100644
index 0000000..84505b7
--- /dev/null
+++ b/0002-add-two-numbers/0002-add-two-numbers.js
@@ -0,0 +1,36 @@
+/**
+ * Definition for singly-linked list.
+ * function ListNode(val, next) {
+ *     this.val = (val===undefined ? 0 : val)
+ *     this.next = (next===undefined ? null : next)
+ * }
+ */
+/**
+ * @param {ListNode} l1
+ * @param {ListNode} l2
+ * @return {ListNode}
+ */
+var addTwoNumbers = function(l1, l2) {
+    let dummy = new ListNode(0);
+    let current = dummy;
+    let carry = 0;
+    
+    while (l1 !== null || l2 !== null || carry !== 0) {
+        let sum = carry;
+        if (l1 !== null) {
+            sum += l1.val;
+            l1 = l1.next;
+        }
+        if (l2 !== null) {
+            sum += l2.val;
+            l2 = l2.next;
+        }
+        
+        carry = Math.floor(sum / 10);
+        sum = sum % 10;
+        current.next = new ListNode(sum);
+        current = current.next;
+    }
+    
+    return dummy.next;
+};
\ No newline at end of file
diff --git a/0002-add-two-numbers/0002-add-two-numbers.php b/0002-add-two-numbers/0002-add-two-numbers.php
new file mode 100644
index 0000000..f32b781
--- /dev/null
+++ b/0002-add-two-numbers/0002-add-two-numbers.php
@@ -0,0 +1,46 @@
+<?php
+
+    /**
+ * Definition for a singly-linked list.
+ * class ListNode {
+ *     public $val = 0;
+ *     public $next = null;
+ *     function __construct($val = 0, $next = null) {
+ *         $this->val = $val;
+ *         $this->next = $next;
+ *     }
+ * }
+ */
+class Solution {
+    /**
+     * @param ListNode $l1
+     * @param ListNode $l2
+     * @return ListNode
+     */
+    function addTwoNumbers($l1, $l2) {
+        $dummy = new ListNode(0);
+        $current = $dummy;
+        $carry = 0;
+        
+        while ($l1 !== null || $l2 !== null || $carry !== 0) {
+            $sum = $carry;
+            if ($l1 !== null) {
+                $sum += $l1->val;
+                $l1 = $l1->next;
+            }
+            if ($l2 !== null) {
+                $sum += $l2->val;
+                $l2 = $l2->next;
+            }
+            
+            $carry = intdiv($sum, 10);
+            $sum = $sum % 10;
+            $current->next = new ListNode($sum);
+            $current = $current->next;
+        }
+        
+        return $dummy->next;
+    }
+}
+
+?>
\ No newline at end of file
diff --git a/0002-add-two-numbers/0002-add-two-numbers.rb b/0002-add-two-numbers/0002-add-two-numbers.rb
new file mode 100644
index 0000000..728dc52
--- /dev/null
+++ b/0002-add-two-numbers/0002-add-two-numbers.rb
@@ -0,0 +1,36 @@
+# Definition for singly-linked list.
+# class ListNode
+#     attr_accessor :val, :next
+#     def initialize(val = 0, _next = nil)
+#         @val = val
+#         @next = _next
+#     end
+# end
+
+# @param {ListNode} l1
+# @param {ListNode} l2
+# @return {ListNode}
+def add_two_numbers(l1, l2)
+    dummy = ListNode.new(0)
+    current = dummy
+    carry = 0
+    
+    while l1 || l2 || carry != 0
+        sum = carry
+        if l1
+            sum += l1.val
+            l1 = l1.next
+        end
+        if l2
+            sum += l2.val
+            l2 = l2.next
+        end
+        
+        carry = sum / 10
+        sum = sum % 10
+        current.next = ListNode.new(sum)
+        current = current.next
+    end
+    
+    dummy.next
+end
\ No newline at end of file
diff --git a/0009-palindrome-number/0009-palindrome-number.js b/0009-palindrome-number/0009-palindrome-number.js
new file mode 100644
index 0000000..e912e3f
--- /dev/null
+++ b/0009-palindrome-number/0009-palindrome-number.js
@@ -0,0 +1,7 @@
+/**
+ * @param {number} x
+ * @return {boolean}
+ */
+var isPalindrome = function(x) {
+    return x.toString().split('').reverse().join('') == x;
+};
\ No newline at end of file
diff --git a/0009-palindrome-number/0009-palindrome-number.rb b/0009-palindrome-number/0009-palindrome-number.rb
new file mode 100644
index 0000000..a9986bf
--- /dev/null
+++ b/0009-palindrome-number/0009-palindrome-number.rb
@@ -0,0 +1,10 @@
+def is_palindrome(x)
+  return false if x < 0
+  reverse = 0
+  original = x
+  while x > 0
+    reverse = reverse * 10 + x % 10
+    x /= 10
+  end
+  reverse == original
+end
\ No newline at end of file
diff --git a/0011-container-with-most-water/0011-container-with-most-water.cs b/0011-container-with-most-water/0011-container-with-most-water.cs
new file mode 100644
index 0000000..cadb707
--- /dev/null
+++ b/0011-container-with-most-water/0011-container-with-most-water.cs
@@ -0,0 +1,22 @@
+public class Solution
+{
+    public int MaxArea(int[] height)
+    {
+        int left = 0;
+        int right = height.Length - 1;
+        int maxArea = 0;
+        while (left < right)
+        {
+            maxArea = Math.Max(maxArea, Math.Min(height[left], height[right]) * (right - left));
+            if (height[left] < height[right])
+            {
+                left++;
+            }
+            else
+            {
+                right--;
+            }
+        }
+        return maxArea;
+    }
+}
\ No newline at end of file
diff --git a/0011-container-with-most-water/0011-container-with-most-water.java b/0011-container-with-most-water/0011-container-with-most-water.java
new file mode 100644
index 0000000..ccba04d
--- /dev/null
+++ b/0011-container-with-most-water/0011-container-with-most-water.java
@@ -0,0 +1,16 @@
+class Solution {
+    public int maxArea(int[] height) {
+        int left = 0;
+        int right = height.length - 1;
+        int maxArea = 0;
+        while (left < right) {
+            maxArea = Math.max(maxArea, Math.min(height[left], height[right]) * (right - left));
+            if (height[left] < height[right]) {
+                left++;
+            } else {
+                right--;
+            }
+        }
+        return maxArea;
+    }
+}
\ No newline at end of file
diff --git a/0011-container-with-most-water/0011-container-with-most-water.php b/0011-container-with-most-water/0011-container-with-most-water.php
new file mode 100644
index 0000000..303da51
--- /dev/null
+++ b/0011-container-with-most-water/0011-container-with-most-water.php
@@ -0,0 +1,25 @@
+<?php
+
+    class Solution {
+
+    /**
+     * @param Integer[] $height
+     * @return Integer
+     */
+    function maxArea($height) {
+        $left = 0;
+        $right = count($height) - 1;
+        $maxArea = 0;
+        while ($left < $right) {
+            $maxArea = max($maxArea, min($height[$left], $height[$right]) * ($right - $left));
+            if ($height[$left] < $height[$right]) {
+                $left++;
+            } else {
+                $right--;
+            }
+        }
+        return $maxArea;
+    }
+}
+
+?>
\ No newline at end of file
diff --git a/0011-container-with-most-water/0011-container-with-most-water.rb b/0011-container-with-most-water/0011-container-with-most-water.rb
new file mode 100644
index 0000000..b0bcc02
--- /dev/null
+++ b/0011-container-with-most-water/0011-container-with-most-water.rb
@@ -0,0 +1,16 @@
+# @param {Integer[]} height
+# @return {Integer}
+def max_area(height)
+    left = 0
+    right = height.length - 1
+    max_area = 0
+    while left < right do
+        max_area = [max_area, [height[left], height[right]].min * (right - left)].max
+        if height[left] < height[right]
+            left += 1
+        else
+            right -= 1
+        end
+    end
+    return max_area
+end
\ No newline at end of file