diff --git a/DSA/Linked_List/define.ipynb b/DSA/Linked_List/define.ipynb
new file mode 100644
index 0000000..19d614c
--- /dev/null
+++ b/DSA/Linked_List/define.ipynb
@@ -0,0 +1,111 @@
+{
+ "cells": [
+  {
+   "cell_type": "code",
+   "execution_count": 8,
+   "metadata": {},
+   "outputs": [],
+   "source": [
+    "class Node:\n",
+    "    def __init__(self, data):\n",
+    "        self.data = data\n",
+    "        self.next = None\n",
+    "\n",
+    "    def __repr__(self):\n",
+    "        return self.data"
+   ]
+  },
+  {
+   "cell_type": "code",
+   "execution_count": 15,
+   "metadata": {},
+   "outputs": [],
+   "source": [
+    "class LinkedList:\n",
+    "    def __init__(self):\n",
+    "        self.head = None\n",
+    "\n",
+    "    def __repr__(self):\n",
+    "        node = self.head\n",
+    "        nodes = []\n",
+    "        while node is not None:\n",
+    "            nodes.append(node.data)\n",
+    "            node = node.next\n",
+    "        nodes.append(\"None\")\n",
+    "        return \" -> \".join(nodes)"
+   ]
+  },
+  {
+   "cell_type": "code",
+   "execution_count": 14,
+   "metadata": {},
+   "outputs": [
+    {
+     "data": {
+      "text/plain": [
+       "None"
+      ]
+     },
+     "execution_count": 14,
+     "metadata": {},
+     "output_type": "execute_result"
+    }
+   ],
+   "source": [
+    "l_list = LinkedList()\n",
+    "l_list"
+   ]
+  },
+  {
+   "cell_type": "code",
+   "execution_count": 19,
+   "metadata": {},
+   "outputs": [],
+   "source": [
+    "first_node = Node(\"a\")\n",
+    "l_list.head = first_node"
+   ]
+  },
+  {
+   "cell_type": "code",
+   "execution_count": 21,
+   "metadata": {},
+   "outputs": [],
+   "source": [
+    "second_node = Node(\"b\")\n",
+    "third_node = Node(\"c\")"
+   ]
+  },
+  {
+   "cell_type": "code",
+   "execution_count": 22,
+   "metadata": {},
+   "outputs": [],
+   "source": [
+    "first_node.next = second_node\n",
+    "second_node.next =third_node"
+   ]
+  }
+ ],
+ "metadata": {
+  "kernelspec": {
+   "display_name": "Python 3",
+   "language": "python",
+   "name": "python3"
+  },
+  "language_info": {
+   "codemirror_mode": {
+    "name": "ipython",
+    "version": 3
+   },
+   "file_extension": ".py",
+   "mimetype": "text/x-python",
+   "name": "python",
+   "nbconvert_exporter": "python",
+   "pygments_lexer": "ipython3",
+   "version": "3.10.4"
+  }
+ },
+ "nbformat": 4,
+ "nbformat_minor": 2
+}
diff --git a/DSA/Linked_List/doughnut.py b/DSA/Linked_List/doughnut.py
new file mode 100644
index 0000000..5a7e998
--- /dev/null
+++ b/DSA/Linked_List/doughnut.py
@@ -0,0 +1,28 @@
+while ('o_' in dir()) or (A := (0)
+               ) or (B := 0) or print((
+            "\x1b[2J")) or not ((sin := ((
+         __import__('math'))).sin)) or not (
+      cos := __import__('math').cos) or (o_ := (
+     True)): [pr() for b in [[(func(), b) for ((z
+    )) in [[0 for _ in range(1760)]] for b in [[ (
+   "\n") if ii % 80 == 79 else " " for ii in range(
+  1760)]] for o, D, N in [(o, D, N) for j in range((
+ 0), 628, 7) for i in range(0, 628, 2) for (c, d, e,(
+f), g, l, m, n) in [(sin(     i / 100), cos(j / 100),(
+sin(A)), sin(j / 100),          cos(A), cos(i / 100) ,
+cos(B), sin(B))] for              (h) in [d + 2] for (
+D, t) in [ (1 / ( c               * h * e + f * g + (5
+)), c * h * g - f *                e)] for (x, y) in [
+(int( 40 + 30 * D * (              l * h * m - t * n)),
+int( 12 + 15 * D * ( l           * h * n + t * (m))))]
+ for (o, N) in [(x + 80 *     y,int(8 * (( f * e -  c
+  * d * g) * m - c * d * e - f * g - l * d * n)))] if
+  0 < x < 80 and 22 > y > 0] if D > z[o] for func in
+   [lambda: (z.pop((o))), lambda: z.insert((o), (D)
+    ),(lambda: (b.pop( o))), lambda: b.insert((o),
+     ".,-~:;=!*#$@"[ N if N > 0 else 0])]][ 0][1]
+       ] for pr in [lambda: print("\x1b[H"),
+         lambda: print("".join(b))] if (A :=
+            A + 0.02) and ( B := B + 0.02)]
+               #..--~~EvanZhouDev:~~--.#
+                    #...,2023,...#
\ No newline at end of file
diff --git a/re_leet_code/merge_two_sorted_lists/main.py b/re_leet_code/merge_two_sorted_lists/main.py
new file mode 100644
index 0000000..f69ca32
--- /dev/null
+++ b/re_leet_code/merge_two_sorted_lists/main.py
@@ -0,0 +1,9 @@
+def mergeTwoLists(list1, list2):
+    list3 = list1 + list2
+    return sorted(list3)
+
+
+list1 = [1, 2, 4]
+list2 = [1, 3, 4]
+
+print(mergeTwoLists(list1, list2))