diff --git a/bit_manipulation/pairwise_swap/__init__.py b/bit_manipulation/pairwise_swap/__init__.py
new file mode 100644
index 0000000..e69de29
diff --git a/bit_manipulation/pairwise_swap/pairwise_swap_challenge.ipynb b/bit_manipulation/pairwise_swap/pairwise_swap_challenge.ipynb
new file mode 100644
index 0000000..6174be8
--- /dev/null
+++ b/bit_manipulation/pairwise_swap/pairwise_swap_challenge.ipynb
@@ -0,0 +1,174 @@
+{
+ "cells": [
+  {
+   "cell_type": "markdown",
+   "metadata": {},
+   "source": [
+    "This notebook was prepared by [Donne Martin](https://github.com/donnemartin). Source and license info is on [GitHub](https://github.com/donnemartin/interactive-coding-challenges)."
+   ]
+  },
+  {
+   "cell_type": "markdown",
+   "metadata": {},
+   "source": [
+    "# Challenge Notebook"
+   ]
+  },
+  {
+   "cell_type": "markdown",
+   "metadata": {},
+   "source": [
+    "## Problem: Swap the odd and even bits of a positive integer with as few operations as possible.\n",
+    "\n",
+    "* [Constraints](#Constraints)\n",
+    "* [Test Cases](#Test-Cases)\n",
+    "* [Algorithm](#Algorithm)\n",
+    "* [Code](#Code)\n",
+    "* [Unit Test](#Unit-Test)\n",
+    "* [Solution Notebook](#Solution-Notebook)"
+   ]
+  },
+  {
+   "cell_type": "markdown",
+   "metadata": {},
+   "source": [
+    "## Constraints\n",
+    "\n",
+    "* Can we assume the input is always a positive int?\n",
+    "    * Yes\n",
+    "* Can we assume we're working with 32 bits?\n",
+    "    * Yes\n",
+    "* Is the output an int?\n",
+    "    * Yes\n",
+    "* Can we assume the inputs are valid (not None)?\n",
+    "    * No\n",
+    "* Can we assume this fits memory?\n",
+    "    * Yes"
+   ]
+  },
+  {
+   "cell_type": "markdown",
+   "metadata": {},
+   "source": [
+    "## Test Cases\n",
+    "\n",
+    "* None -> Exception\n",
+    "* 0 -> 0\n",
+    "* -1 -> -1\n",
+    "* General case\n",
+    "<pre>\n",
+    "    input  = 1001 1111 0110\n",
+    "    result = 0110 1111 1001\n",
+    "<pre>"
+   ]
+  },
+  {
+   "cell_type": "markdown",
+   "metadata": {},
+   "source": [
+    "## Algorithm\n",
+    "\n",
+    "Refer to the [Solution Notebook]().  If you are stuck and need a hint, the solution notebook's algorithm discussion might be a good place to start."
+   ]
+  },
+  {
+   "cell_type": "markdown",
+   "metadata": {},
+   "source": [
+    "## Code"
+   ]
+  },
+  {
+   "cell_type": "code",
+   "execution_count": null,
+   "metadata": {
+    "collapsed": false
+   },
+   "outputs": [],
+   "source": [
+    "class Bits(object):\n",
+    "\n",
+    "    def pairwise_swap(self, num):\n",
+    "        # TODO: Implement me\n",
+    "        pass"
+   ]
+  },
+  {
+   "cell_type": "markdown",
+   "metadata": {},
+   "source": [
+    "## Unit Test"
+   ]
+  },
+  {
+   "cell_type": "markdown",
+   "metadata": {},
+   "source": [
+    "**The following unit test is expected to fail until you solve the challenge.**"
+   ]
+  },
+  {
+   "cell_type": "code",
+   "execution_count": null,
+   "metadata": {
+    "collapsed": false
+   },
+   "outputs": [],
+   "source": [
+    "# %load test_pairwise_swap.py\n",
+    "from nose.tools import assert_equal\n",
+    "\n",
+    "\n",
+    "class TestBits(object):\n",
+    "\n",
+    "    def test_pairwise_swap(self):\n",
+    "        bits = Bits()\n",
+    "        assert_equal(bits.pairwise_swap(0), 0)\n",
+    "        assert_equal(bits.pairwise_swap(1), 1)\n",
+    "        num = int('0000100111110110', base=2)\n",
+    "        expected = int('0000011011111001', base=2)\n",
+    "        assert_equal(bits.pairwise_swap(num), expected)\n",
+    "        print('Success: test_pairwise_swap')\n",
+    "\n",
+    "\n",
+    "def main():\n",
+    "    test = TestBits()\n",
+    "    test.test_pairwise_swap()\n",
+    "\n",
+    "\n",
+    "if __name__ == '__main__':\n",
+    "    main()"
+   ]
+  },
+  {
+   "cell_type": "markdown",
+   "metadata": {},
+   "source": [
+    "## Solution Notebook\n",
+    "\n",
+    "Review the [Solution Notebook]() for a discussion on algorithms and code solutions."
+   ]
+  }
+ ],
+ "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": "3.5.0"
+  }
+ },
+ "nbformat": 4,
+ "nbformat_minor": 0
+}
diff --git a/bit_manipulation/pairwise_swap/pairwise_swap_solution.ipynb b/bit_manipulation/pairwise_swap/pairwise_swap_solution.ipynb
new file mode 100644
index 0000000..9de5545
--- /dev/null
+++ b/bit_manipulation/pairwise_swap/pairwise_swap_solution.ipynb
@@ -0,0 +1,219 @@
+{
+ "cells": [
+  {
+   "cell_type": "markdown",
+   "metadata": {},
+   "source": [
+    "This notebook was prepared by [Donne Martin](https://github.com/donnemartin). Source and license info is on [GitHub](https://github.com/donnemartin/interactive-coding-challenges)."
+   ]
+  },
+  {
+   "cell_type": "markdown",
+   "metadata": {},
+   "source": [
+    "# Solution Notebook"
+   ]
+  },
+  {
+   "cell_type": "markdown",
+   "metadata": {},
+   "source": [
+    "## Problem: Swap the odd and even bits of a positive integer with as few operations as possible.\n",
+    "\n",
+    "* [Constraints](#Constraints)\n",
+    "* [Test Cases](#Test-Cases)\n",
+    "* [Algorithm](#Algorithm)\n",
+    "* [Code](#Code)\n",
+    "* [Unit Test](#Unit-Test)"
+   ]
+  },
+  {
+   "cell_type": "markdown",
+   "metadata": {},
+   "source": [
+    "## Constraints\n",
+    "\n",
+    "* Can we assume the input is always a positive int?\n",
+    "    * Yes\n",
+    "* Can we assume we're working with 32 bits?\n",
+    "    * Yes\n",
+    "* Is the output an int?\n",
+    "    * Yes\n",
+    "* Can we assume the inputs are valid (not None)?\n",
+    "    * No\n",
+    "* Can we assume this fits memory?\n",
+    "    * Yes"
+   ]
+  },
+  {
+   "cell_type": "markdown",
+   "metadata": {},
+   "source": [
+    "## Test Cases\n",
+    "\n",
+    "* None -> Exception\n",
+    "* 0 -> 0\n",
+    "* -1 -> -1\n",
+    "* General case\n",
+    "<pre>\n",
+    "    input  = 0000 1001 1111 0110\n",
+    "    result = 0000 0110 1111 1001\n",
+    "<pre>"
+   ]
+  },
+  {
+   "cell_type": "markdown",
+   "metadata": {},
+   "source": [
+    "## Algorithm\n",
+    "\n",
+    "<pre>\n",
+    "* Isolate the odd bits with a mask:\n",
+    "    0000 1001 1111 0110  num\n",
+    "    1010 1010 1010 1010  mask\n",
+    "    --------------------------------\n",
+    "    0000 1000 1010 0010  num & mask\n",
+    "\n",
+    "* Shift the odd bits right:\n",
+    "    0000 0100 0101 0001  odd\n",
+    "\n",
+    "* Isolate the even bits with a mask:\n",
+    "    0000 1001 1111 0110  num\n",
+    "    0101 0101 0101 0101  mask\n",
+    "    --------------------------------\n",
+    "    0000 0001 0101 0100  num & mask\n",
+    "\n",
+    "* Shift the even bits left:\n",
+    "    0000 0010 1010 1000  even\n",
+    "\n",
+    "* Return even | odd\n",
+    "    0000 0100 0101 0001  odd\n",
+    "    0000 0010 1010 1000  even\n",
+    "    --------------------------------\n",
+    "    0000 0110 1111 1001  odd | even\n",
+    "</pre>\n",
+    "\n",
+    "Complexity:\n",
+    "* Time: O(b), where b is the number of bits\n",
+    "* Space: O(b), where b is the number of bits"
+   ]
+  },
+  {
+   "cell_type": "markdown",
+   "metadata": {},
+   "source": [
+    "## Code"
+   ]
+  },
+  {
+   "cell_type": "code",
+   "execution_count": 1,
+   "metadata": {
+    "collapsed": false
+   },
+   "outputs": [],
+   "source": [
+    "class Bits(object):\n",
+    "\n",
+    "    def pairwise_swap(self, num):\n",
+    "        if num is None:\n",
+    "            raise TypeError('num cannot be None')\n",
+    "        if num == 0 or num == 1:\n",
+    "            return num\n",
+    "        odd = (num & int('1010101010101010', base=2)) >> 1\n",
+    "        even = (num & int('0101010101010101', base=2)) << 1\n",
+    "        return odd | even"
+   ]
+  },
+  {
+   "cell_type": "markdown",
+   "metadata": {},
+   "source": [
+    "## Unit Test"
+   ]
+  },
+  {
+   "cell_type": "code",
+   "execution_count": 2,
+   "metadata": {
+    "collapsed": false
+   },
+   "outputs": [
+    {
+     "name": "stdout",
+     "output_type": "stream",
+     "text": [
+      "Overwriting test_pairwise_swap.py\n"
+     ]
+    }
+   ],
+   "source": [
+    "%%writefile test_pairwise_swap.py\n",
+    "from nose.tools import assert_equal, assert_raises\n",
+    "\n",
+    "\n",
+    "class TestBits(object):\n",
+    "\n",
+    "    def test_pairwise_swap(self):\n",
+    "        bits = Bits()\n",
+    "        assert_equal(bits.pairwise_swap(0), 0)\n",
+    "        assert_equal(bits.pairwise_swap(1), 1)\n",
+    "        num = int('0000100111110110', base=2)\n",
+    "        expected = int('0000011011111001', base=2)\n",
+    "        assert_equal(bits.pairwise_swap(num), expected)\n",
+    "        assert_raises(TypeError, bits.pairwise_swap, None)\n",
+    "        \n",
+    "        print('Success: test_pairwise_swap')\n",
+    "\n",
+    "\n",
+    "def main():\n",
+    "    test = TestBits()\n",
+    "    test.test_pairwise_swap()\n",
+    "\n",
+    "\n",
+    "if __name__ == '__main__':\n",
+    "    main()"
+   ]
+  },
+  {
+   "cell_type": "code",
+   "execution_count": 3,
+   "metadata": {
+    "collapsed": false
+   },
+   "outputs": [
+    {
+     "name": "stdout",
+     "output_type": "stream",
+     "text": [
+      "Success: test_pairwise_swap\n"
+     ]
+    }
+   ],
+   "source": [
+    "%run -i test_pairwise_swap.py"
+   ]
+  }
+ ],
+ "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": "3.5.0"
+  }
+ },
+ "nbformat": 4,
+ "nbformat_minor": 0
+}
diff --git a/bit_manipulation/pairwise_swap/test_pairwise_swap.py b/bit_manipulation/pairwise_swap/test_pairwise_swap.py
new file mode 100644
index 0000000..5ee4cae
--- /dev/null
+++ b/bit_manipulation/pairwise_swap/test_pairwise_swap.py
@@ -0,0 +1,24 @@
+from nose.tools import assert_equal, assert_raises
+
+
+class TestBits(object):
+
+    def test_pairwise_swap(self):
+        bits = Bits()
+        assert_equal(bits.pairwise_swap(0), 0)
+        assert_equal(bits.pairwise_swap(1), 1)
+        num = int('0000100111110110', base=2)
+        expected = int('0000011011111001', base=2)
+        assert_equal(bits.pairwise_swap(num), expected)
+        assert_raises(TypeError, bits.pairwise_swap, None)
+        
+        print('Success: test_pairwise_swap')
+
+
+def main():
+    test = TestBits()
+    test.test_pairwise_swap()
+
+
+if __name__ == '__main__':
+    main()
\ No newline at end of file