{
 "metadata": {
  "name": "",
  "signature": "sha256:0436e72f1d4aba99574ecd8525b1de6b98fb1fd8eb76582449c2750dede80702"
 },
 "nbformat": 3,
 "nbformat_minor": 0,
 "worksheets": [
  {
   "cells": [
    {
     "cell_type": "code",
     "collapsed": false,
     "input": [
      "import time\n",
      "\n",
      "start = time.time()\n",
      "Fn_1 = 1\n",
      "Fn  = 2\n",
      "fib_sum = 0\n",
      "while(Fn < 4e6):\n",
      "    if Fn%2==0:\n",
      "        fib_sum += Fn\n",
      "    Fn, Fn_1 = Fn+Fn_1, Fn \n",
      "\n",
      "print \"Answer:{}\".format( fib_sum )\n",
      "print \"Elapsed time:{0} seconds\".format(time.time()-start)"
     ],
     "language": "python",
     "metadata": {},
     "outputs": [
      {
       "output_type": "stream",
       "stream": "stdout",
       "text": [
        "Answer:4613732\n",
        "Elapsed time:0.000380992889404 seconds\n"
       ]
      }
     ],
     "prompt_number": 1
    },
    {
     "cell_type": "code",
     "collapsed": false,
     "input": [],
     "language": "python",
     "metadata": {},
     "outputs": [],
     "prompt_number": 1
    },
    {
     "cell_type": "code",
     "collapsed": false,
     "input": [],
     "language": "python",
     "metadata": {},
     "outputs": []
    }
   ],
   "metadata": {}
  }
 ]
}