diff --git a/src/AoC_2024/Dazbo's_Advent_of_Code_2024.ipynb b/src/AoC_2024/Dazbo's_Advent_of_Code_2024.ipynb
index e62c2e1..d45b698 100644
--- a/src/AoC_2024/Dazbo's_Advent_of_Code_2024.ipynb
+++ b/src/AoC_2024/Dazbo's_Advent_of_Code_2024.ipynb
@@ -1058,6 +1058,317 @@
     "logger.info(f\"Part 2 soln={soln}\")"
    ]
   },
+  {
+   "cell_type": "markdown",
+   "metadata": {},
+   "source": [
+    "---\n",
+    "## Day 3: Mull It Over"
+   ]
+  },
+  {
+   "cell_type": "code",
+   "execution_count": null,
+   "metadata": {},
+   "outputs": [],
+   "source": [
+    "DAY = \"3\" # replace with actual number (without leading digit)\n",
+    "day_link = f\"#### See [Day {DAY}](https://adventofcode.com/{YEAR}/day/{DAY}).\"\n",
+    "display(Markdown(day_link))"
+   ]
+  },
+  {
+   "cell_type": "code",
+   "execution_count": null,
+   "metadata": {},
+   "outputs": [],
+   "source": [
+    "d_name = \"d\" + str(DAY).zfill(2) # e.g. d01\n",
+    "script_name = \"aoc\" + str(YEAR) + d_name # e.g. aoc2024d01\n",
+    "locations = dc.get_locations(d_name)\n",
+    "logger.setLevel(logging.DEBUG)\n",
+    "# td.setup_file_logging(logger, locations.output_dir)\n",
+    "\n",
+    "# Retrieve input and store in local file\n",
+    "try:\n",
+    "    write_puzzle_input_file(YEAR, DAY, locations)\n",
+    "    with open(locations.input_file, mode=\"rt\") as f:\n",
+    "        input_data = f.read()\n",
+    "\n",
+    "    logger.info(\"Input data:\\n%s\", dc.top_and_tail(input_data))\n",
+    "except ValueError as e:\n",
+    "    logger.error(e)"
+   ]
+  },
+  {
+   "cell_type": "markdown",
+   "metadata": {},
+   "source": [
+    "### Day 3 Part 1\n",
+    "\n",
+    "A shop computer is trying to run a program, but its memory - the puzzle input - is corrupted.\n",
+    "\n",
+    "It should be doing instructions like:\n",
+    "\n",
+    "- `mul(X,Y)` where `X` and `Y` are 1-3 digit numbers.\n",
+    "\n",
+    "Our instructions:\n",
+    "\n",
+    "- There are many invalid characters which should be ignored.\n",
+    "- If an invalid character is part of a `mul()` instruction, then the whole instruction does nothing.\n",
+    "- Scan the corrupted memory for uncorrupted mul instructions.\n",
+    "\n",
+    "**What do you get if you add up all of the results of the multiplications?**\n",
+    "\n",
+    "#### Solution Approach\n",
+    "\n",
+    "We can just use [regex](https://aoc.just2good.co.uk/python/regex).\n",
+    "\n",
+    "- Use a regex pattern to identify substrints that match the required input format.\n",
+    "- Use the regex `finditer()` to retrieve all non-overlapping matches.\n",
+    "- The `matches.groups()` retrieves the captured groups, i.e. the digits themselves. We identify capture groups by placing each digit in brackets in the pattern string.\n",
+    "- Then, multiply the two digits together, as required."
+   ]
+  },
+  {
+   "cell_type": "code",
+   "execution_count": null,
+   "metadata": {},
+   "outputs": [],
+   "source": [
+    "def solve_part1(data):\n",
+    "    # match all \"mul(x,y)\"\n",
+    "    matches = re.finditer(r\"mul\\((\\d{1,3}),(\\d{1,3})\\)\", data)\n",
+    "    \n",
+    "    ans = 0\n",
+    "    for match in matches:\n",
+    "        val_x, val_y = match.groups()\n",
+    "        ans += int(val_x)*int(val_y)\n",
+    "        \n",
+    "    return ans\n"
+   ]
+  },
+  {
+   "cell_type": "code",
+   "execution_count": null,
+   "metadata": {},
+   "outputs": [],
+   "source": [
+    "%%time\n",
+    "sample_inputs = []\n",
+    "sample_inputs.append(\"\"\"xmul(2,4)%&mul[3,7]!@^do_not_mul(5,5)+mul(32,64]then(mul(11,8)mul(8,5))\"\"\")\n",
+    "sample_answers = [161]\n",
+    "\n",
+    "for curr_input, curr_ans in zip(sample_inputs, sample_answers):\n",
+    "    validate(solve_part1(curr_input), curr_ans) # test with sample data\n",
+    "    logger.info(\"Test passed\")\n",
+    "\n",
+    "logger.info(\"All tests passed!\")\n",
+    "\n",
+    "soln = solve_part1(input_data)\n",
+    "logger.info(f\"Part 1 soln={soln}\")"
+   ]
+  },
+  {
+   "cell_type": "markdown",
+   "metadata": {},
+   "source": [
+    "### Day 3 Part 2\n",
+    "\n",
+    "Now we also want to handle intact conditional statements. We need to handle:\n",
+    "\n",
+    "- `do()` which enables future `mul` instructions\n",
+    "- `don't()` which disables future `mul` instructions.\n",
+    "\n",
+    "We start enabled.\n",
+    "\n",
+    "**What is the sum of just the enabled multiplications?**\n",
+    "\n",
+    "#### Solution Approach\n",
+    "\n",
+    "- Okay, we start `enabled`.\n",
+    "- Whilst `enabled==True`, everything up to the next `don't()` should be parsed for `mul()` instructions.\n",
+    "- When we hit a `don't()`, we set `enabled=False`.\n",
+    "- Now, everything up to the next `do()` should be ignored.\n",
+    "- When we hit a `do()`, we set `enabled=True` again.\n",
+    "\n",
+    "I'm shocked... This worked first time with no bugs!!"
+   ]
+  },
+  {
+   "cell_type": "code",
+   "execution_count": null,
+   "metadata": {},
+   "outputs": [],
+   "source": [
+    "def solve_part2(data: str):\n",
+    "    # match all \"mul(x,y)\"\n",
+    "    matcher = re.compile(r\"mul\\((\\d{1,3}),(\\d{1,3})\\)\")\n",
+    "    \n",
+    "    remaining_program = data\n",
+    "    enabled = True # We start enabled\n",
+    "    ans = 0\n",
+    "    while remaining_program:\n",
+    "        if enabled:\n",
+    "            # split into the part before the next \"don't()\", and everything afterwards\n",
+    "            this_part, _, remaining_program = remaining_program.partition(r\"don't()\")\n",
+    "        \n",
+    "            for match in matcher.finditer(this_part):\n",
+    "                val_x, val_y = match.groups()\n",
+    "                ans += int(val_x)*int(val_y)\n",
+    "            \n",
+    "            enabled = False\n",
+    "        else:\n",
+    "            # split into the part before the next \"do()\", and everything afterwards\n",
+    "            this_part, _, remaining_program = remaining_program.partition(r\"do()\")\n",
+    "            enabled = True\n",
+    "        \n",
+    "    return ans"
+   ]
+  },
+  {
+   "cell_type": "code",
+   "execution_count": null,
+   "metadata": {},
+   "outputs": [],
+   "source": [
+    "%%time\n",
+    "sample_inputs = []\n",
+    "sample_inputs.append(\"\"\"xmul(2,4)&mul[3,7]!^don't()_mul(5,5)+mul(32,64](mul(11,8)undo()?mul(8,5))\"\"\")\n",
+    "sample_answers = [48]\n",
+    "\n",
+    "for curr_input, curr_ans in zip(sample_inputs, sample_answers):\n",
+    "    validate(solve_part2(curr_input), curr_ans) # test with sample data\n",
+    "    logger.info(\"Test passed\")    \n",
+    "\n",
+    "logger.info(\"Tests passed!\")\n",
+    "\n",
+    "soln = solve_part2(input_data)\n",
+    "logger.info(f\"Part 2 soln={soln}\")"
+   ]
+  },
+  {
+   "cell_type": "markdown",
+   "metadata": {},
+   "source": [
+    "---\n",
+    "## Day 4: title"
+   ]
+  },
+  {
+   "cell_type": "code",
+   "execution_count": null,
+   "metadata": {},
+   "outputs": [],
+   "source": [
+    "DAY = \"4\" # replace with actual number (without leading digit)\n",
+    "day_link = f\"#### See [Day {DAY}](https://adventofcode.com/{YEAR}/day/{DAY}).\"\n",
+    "display(Markdown(day_link))"
+   ]
+  },
+  {
+   "cell_type": "code",
+   "execution_count": null,
+   "metadata": {},
+   "outputs": [],
+   "source": [
+    "d_name = \"d\" + str(DAY).zfill(2) # e.g. d01\n",
+    "script_name = \"aoc\" + str(YEAR) + d_name # e.g. aoc2024d01\n",
+    "locations = dc.get_locations(d_name)\n",
+    "logger.setLevel(logging.DEBUG)\n",
+    "# td.setup_file_logging(logger, locations.output_dir)\n",
+    "\n",
+    "# Retrieve input and store in local file\n",
+    "try:\n",
+    "    write_puzzle_input_file(YEAR, DAY, locations)\n",
+    "    with open(locations.input_file, mode=\"rt\") as f:\n",
+    "        input_data = f.read().splitlines()\n",
+    "\n",
+    "    logger.info(\"Input data:\\n%s\", dc.top_and_tail(input_data))\n",
+    "except ValueError as e:\n",
+    "    logger.error(e)"
+   ]
+  },
+  {
+   "cell_type": "markdown",
+   "metadata": {},
+   "source": [
+    "### Day 4 Part 1\n",
+    "\n",
+    "Overview..."
+   ]
+  },
+  {
+   "cell_type": "code",
+   "execution_count": null,
+   "metadata": {},
+   "outputs": [],
+   "source": [
+    "def solve_part1(data):\n",
+    "    pass"
+   ]
+  },
+  {
+   "cell_type": "code",
+   "execution_count": null,
+   "metadata": {},
+   "outputs": [],
+   "source": [
+    "%%time\n",
+    "sample_inputs = []\n",
+    "sample_inputs.append(\"\"\"abcdef\"\"\")\n",
+    "sample_answers = [\"uvwxyz\"]\n",
+    "\n",
+    "for curr_input, curr_ans in zip(sample_inputs, sample_answers):\n",
+    "    validate(solve_part1(curr_input), curr_ans) # test with sample data\n",
+    "    logger.info(\"Test passed\")\n",
+    "\n",
+    "logger.info(\"All tests passed!\")\n",
+    "\n",
+    "soln = solve_part1(input_data)\n",
+    "logger.info(f\"Part 1 soln={soln}\")"
+   ]
+  },
+  {
+   "cell_type": "markdown",
+   "metadata": {},
+   "source": [
+    "### Day 4 Part 2\n",
+    "\n",
+    "Overview..."
+   ]
+  },
+  {
+   "cell_type": "code",
+   "execution_count": null,
+   "metadata": {},
+   "outputs": [],
+   "source": [
+    "def solve_part2(data):\n",
+    "    pass"
+   ]
+  },
+  {
+   "cell_type": "code",
+   "execution_count": null,
+   "metadata": {},
+   "outputs": [],
+   "source": [
+    "%%time\n",
+    "sample_inputs = []\n",
+    "sample_inputs.append(\"\"\"abcdef\"\"\")\n",
+    "sample_answers = [\"uvwxyz\"]\n",
+    "\n",
+    "for curr_input, curr_ans in zip(sample_inputs, sample_answers):\n",
+    "    validate(solve_part2(curr_input), curr_ans) # test with sample data\n",
+    "    logger.info(\"Test passed\")    \n",
+    "\n",
+    "logger.info(\"Tests passed!\")\n",
+    "\n",
+    "soln = solve_part2(input_data)\n",
+    "logger.info(f\"Part 2 soln={soln}\")"
+   ]
+  },
   {
    "cell_type": "markdown",
    "metadata": {},
diff --git a/src/AoC_2024/d03/input/input.txt b/src/AoC_2024/d03/input/input.txt
new file mode 100644
index 0000000..301347f
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