#!/usr/bin/env python

plaintext = \
  '"I hesitated\r' \
  'before untying the bow\r' \
  'that bound this book together.\r' \
  '\r' \
  'A black book:\r' \
  '    ALBUMS\r' \
  'CA. AGRIPPA\r' \
  '   Order Extra Leaves\r' \
  '      By Letter and Name\r' \
  '\r' \
  'A Kodak album of time-burned\r' \
  'black construction paper\r' \
  '\r' \
  'The string he tied\r' \
  'Has been unravelled by years\r' \
  'and the dry weather of trunks\r' \
  "Like a lady's shoestring from the First World War\r" \
  'Its metal ferrules eaten by oxygen\r' \
  'Until they resemble cigarette-ash\r' \
  '\r' \
  'Inside the cover he inscribed something in soft graphite\r' \
  'Now lost\r' \
  'Then his name\r' \
  'W.F. Gibson Jr.\r' \
  'and something, comma,\r' \
  '1924\r' \
  '\r' \
  'Then he glued his Kodak prints down\r' \
  'And wrote under them\r' \
  'in chalk-like white pencil:\r' \
  '"Papa\'s saw mill, Aug. 1919."\r' \
  '\r' \
  'A flat-roofed shack\r' \
  'Against a mountain ridge\r' \
  'In the foreground are tumbled boards and offcuts\r' \
  'He must have smelled the pitch, in August\r' \
  'The sweet hot reek\r' \
  'Of the electric saw\r' \
  'Biting into decades\r' \
  '\r' \
  '\r' \
  'Next the spaniel Moko\r' \
  '"Moko 1919"\r' \
  'Poses on small bench or table\r' \
  'Before a backyard tree\r' \
  'His coat is lustrous \r' \
  'The grass needs cutting\r' \
  'Beyond the tree,\r' \
  'In eerie Kodak clarity,\r' \
  'Are the summer backstairs of Wheeling,\r' \
  '        West Virginia\r' \
  "Someone's left a wooden stepladder out\r" \
  '\r' \
  '"Aunt Fran and [obscured]"\r' \
  "Although he isn't, this gent\r" \
  'He has a "G" belt-buckle\r' \
  'A lapel-device of Masonic origin\r' \
  'A patent propelling-pencil\r' \
  'A fountain-pen\r' \
  'And the flowers they pose behind so solidly\r' \
  'Are rooted in an upright length of whitewashed\r' \
  '         concrete sewer-pipe.\r' \
  '\r' \
  'Daddy had a horse named Dixie\r' \
  '"Ford on Dixie 1917"\r' \
  'A saddle-blanket marked with a single star\r' \
  'Corduroy jodpurs\r' \
  'A western saddle\r' \
  'And a cloth cap\r' \
  'Proud and happy\r' \
  'As any boy could be\r' \
  '\r' \
  '"Arthur and Ford fishing 1919"\r' \
  'Shot by an adult\r' \
  '(Witness the steady hand\r' \
  'that captures the wildflowers\r' \
  'the shadows on their broad straw hats\r' \
  'reflections of a split-rail fence)\r' \
  'standing opposite them,\r' \
  'on the far side of the pond,\r' \
  'amid the snake-doctors and the mud,\r' \
  'Kodak in hand,\r' \
  'Ford Sr.?\r' \
  '\r' \
  'And "Moma July, 1919"\r' \
  'strolls beside the pond,\r' \
  'in white big city shoes,\r' \
  'Purse tucked behind her,\r' \
  'While either Ford or Arthur, still straw-hatted,\r' \
  'approaches a canvas-topped touring car.\r' \
  '\r' \
  '"Moma and Mrs. Graham at fish hatchery 1919"\r' \
  '  Moma and Mrs. G. sit atop a graceful concrete\r' \
  '        arch.\r' \
  '\r' \
  '"Arthur on Dixie", likewise 1919,\r' \
  '        rather ill at ease.\r' \
  'On the roof behind the barn, behind him,\r' \
  'can be made out this cryptic mark:\r' \
  'H.V.J.M.[?]\r' \
  '\r' \
  '"Papa\'s Mill 1919", my grandfather most regal amid a wrack of\r' \
  'cut lumber,\r' \
  'might as easily be the record\r' \
  'of some later demolition, and\r' \
  'His cotton sleeves are rolled\r' \
  'to but not past the elbow,\r' \
  'striped, with a white neckband\r' \
  'for the attachment of a collar.\r' \
  'Behind him stands a cone of sawdust some thirty feet in height.\r' \
  '(How that feels to tumble down,\r' \
  'or smells when it is wet)\r' \
  '\r' \
  '\r' \
  '                         II.\r' \
  '\r' \
  'The mechanism: stamped black tin,\r' \
  'Leatherette over cardboard, bits of boxwood,\r' \
  'A lens\r' \
  'The shutter falls\r' \
  'Forever\r' \
  'Dividing that from this.\r' \
  '\r' \
  'Now in high-ceiling bedrooms,\r' \
  'unoccupied, unvisited,\r' \
  'in the bottom drawers of veneered bureaus\r' \
  'in cool chemical darkness curl commemorative\r' \
  "montages of the country's World War dead,\r" \
  '\r' \
  'just as I myself discovered\r' \
  'one other summer in an attic trunk,\r' \
  "and beneath that every boy's best treasure\r" \
  'of tarnished actual ammunition\r' \
  'real little bits of war\r' \
  'but also\r' \
  'the mechanism\r' \
  'itself.\r' \
  '\r' \
  'The blued finish of firearms\r' \
  'is a process, controlled, derived from common\r' \
  '         rust, but there\r' \
  'under so rare and uncommon a patina\r' \
  'that many years untouched\r' \
  'until I took it up\r' \
  'and turning, entranced, down the unpainted\r' \
  '          stair,\r' \
  'to the hallway where I swear\r' \
  'I never heard the first shot.\r' \
  '\r' \
  'The copper-jacketed slug recovered\r' \
  "from the bathroom's cardboard cylinder of\r" \
  "         Morton's Salt\r" \
  'was undeformed\r' \
  'save for the faint bright marks of lands\r' \
  '        and grooves\r' \
  'so hot, stilled energy,\r' \
  'it blistered my hand.\r' \
  '\r' \
  'The gun lay on the dusty carpet.\r' \
  'Returning in utter awe I took it so carefully up\r' \
  'That the second shot, equally unintended,\r' \
  '        notched the hardwood bannister and brought\r' \
  '        a strange bright smell of ancient sap to life\r' \
  '        in a beam of dusty sunlight.\r' \
  '        Absolutely alone\r' \
  '        in awareness of the mechanism.\r' \
  '\r' \
  'Like the first time you put your mouth\r' \
  '        on a woman.\r' \
  '\r' \
  '\r' \
  '                     III.\r' \
  '\r' \
  '"Ice Gorge at Wheeling\r' \
  '                 1917"\r' \
  '\r' \
  'Iron bridge in the distance,\r' \
  'Beyond it a city.\r' \
  'Hotels where pimps went about their business\r' \
  'on the sidewalks of a lost world.\r' \
  'But the foreground is in focus,\r' \
  "this corner of carpenter's Gothic,\r" \
  'these backyards running down to the freeze.\r' \
  '\r' \
  '"Steamboat on Ohio River",\r' \
  'its smoke foul and dark,\r' \
  'its year unknown,\r' \
  'beyond it the far bank\r' \
  'overgrown with factories.\r' \
  '\r' \
  '"Our Wytheville\r' \
  'House Sept 1921"\r' \
  '\r' \
  'They have moved down from Wheeling and my father wears his\r' \
  'city clothes. Main Street is unpaved and an electric streetlamp is\r' \
  'slung high in the frame, centered above the tracked dust on a\r' \
  'slack wire, suggesting the way it might pitch in a strong wind,\r' \
  'the shadows that might throw.\r' \
  '\r' \
  'The house is heavy, unattractive, sheathed in stucco, not native\r' \
  'to the region. My grandfather, who sold supplies to contractors,\r' \
  'was prone to modern materials, which he used with\r' \
  "wholesaler's enthusiasm. In 1921 he replaced the section of brick\r" \
  'sidewalk in front of his house with the broad smooth slab of poured\r' \
  'concrete, signing this improvement with a flourish, "W.F.\r' \
  'Gibson 1921". He believed in concrete and plywood\r' \
  'particularly. Seventy years later his signature remains, the slab\r' \
  'floating perfectly level and charmless between mossy stretches of\r' \
  'sweet uneven brick that knew the iron shoes of Yankee horses.\r' \
  '\r' \
  '"Mama Jan. 1922" has come out to sweep the concrete with a \r' \
  'broom. Her boots are fastened with buttons requiring a special instrument.\r' \
  '\r' \
  'Ice gorge again, the Ohio, 1917. The mechanism closes. A\r' \
  'torn clipping offers a 1957 DeSOTO FIREDOME, 4-door Sedan,\r' \
  'torqueflite radio, heater and power steering and brakes, new\r' \
  'w.s.w. premium tires. One owner. $1,595.\r' \
  '\r' \
  '\r' \
  '                                      IV.\r' \
  '\r' \
  'He made it to the age of torqueflite radio\r' \
  'but not much past that, and never in that town.\r' \
  'That was mine to know, Main Street lined with\r' \
  'Rocket Eighty-eights,\r' \
  'the dimestore floored with wooden planks\r' \
  'pies under plastic in the Soda Shop,\r' \
  'and the mystery untold, the other thing,\r' \
  'sensed in the creaking of a sign after midnight\r' \
  'when nobody else was there.\r' \
  '\r' \
  'In the talc-fine dust beneath the platform of the\r' \
  '          Norfolk & Western\r' \
  'lay indian-head pennies undisturbed since\r' \
  '          the dawn of man.\r' \
  '\r' \
  'In the banks and courthouse, a fossil time\r' \
  '          prevailed, limestone centuries.\r' \
  '\r' \
  'When I went up to Toronto\r' \
  '         in the draft,\r' \
  'my Local Board was there on Main Street,\r' \
  'above a store that bought and sold pistols.\r' \
  "I'd once traded that man a derringer for a\r" \
  '        Walther P-38.\r' \
  'The pistols were in the window\r' \
  'behind an amber roller-blind\r' \
  '        like sunglasses.\r' \
  'I was seventeen or so but basically I guess\r' \
  'you just had to be a white boy.\r' \
  "I'd hike out to a shale pit and run\r" \
  'ten dollars worth of 9mm\r' \
  'through it, so worn you hardly\r' \
  'had to pull the trigger.\r' \
  'Bored, tried shooting \r' \
  'down into a distant stream but\r' \
  'one of them came back at me\r' \
  'off a round of river rock\r' \
  'clipping walnut twigs from a branch\r' \
  'two feet above my head.\r' \
  'So that I remembered the mechanism.\r' \
  '\r' \
  '\r' \
  '                             V.\r' \
  '\r' \
  'In the all night bus station\r' \
  'they sold scrambled eggs to state troopers\r' \
  'the long skinny clasp-knives called fruit knives\r' \
  'which were pearl handled watermelon-slicers\r' \
  'and hillbilly novelties in brown varnished wood\r' \
  'which were made in Japan.\r' \
  '\r' \
  "First I'd be sent there at night only\r" \
  "if Mom's carton of Camels ran out,\r" \
  'but gradually I came to value\r' \
  'the submarine light, the alien reek\r' \
  'of the long human haul, the strangers\r' \
  'straight down from Port Authority\r' \
  'headed for Nashville, Memphis, Miami.\r' \
  'Sometimes the Sheriff watched them get off\r' \
  'making sure they got back on.\r' \
  '\r' \
  'When the colored restroom\r' \
  'was no longer required\r' \
  'they knocked open the cinderblock\r' \
  'and extended the magazine rack\r' \
  'to new dimensions,\r' \
  'a cool fluorescent cave of dreams\r' \
  'smelling faintly and forever of disinfectant,\r' \
  'perhaps as well of the travelled fears\r' \
  'of those dark uncounted others who,\r' \
  'moving as through contours of hot iron,\r' \
  'were made thus to dance\r' \
  'or not to dance\r' \
  'as the law saw fit.\r' \
  '\r' \
  'There it was that I was marked out as a writer, \r' \
  'having discovered in that alcove\r' \
  'copies of certain magazines\r' \
  'esoteric and precious, and, yes,\r' \
  'I knew then, knew utterly,\r' \
  'the deal done in my heart forever,\r' \
  'though how I knew not,\r' \
  'nor ever have.\r' \
  '\r' \
  'Walking home\r' \
  'through all the streets unmoving\r' \
  'so quiet I could hear the timers of the traffic lights a block away:\r' \
  '        the mechanism.\r' \
  'Nobody else, just the silence\r' \
  '        spreading out\r' \
  'to where the long trucks groaned\r' \
  '        on the highway\r' \
  'their vast brute souls in want.\r' \
  '\r' \
  '\r' \
  '                                 VI.\r' \
  '\r' \
  'There must have been a true last time\r' \
  "I saw the station but I don't remember\r" \
  'I remember the stiff black horsehide coat\r' \
  'gift in Tucson of a kid named Natkin\r' \
  'I remember the cold\r' \
  'I remember the Army duffle\r' \
  'that was lost and the black man in Buffalo\r' \
  'trying to sell me a fine diamond ring,\r' \
  'and in the coffee shop in Washington\r' \
  "I'd eavesdropped on a man wearing a black tie\r" \
  'embroidered with red roses\r' \
  'that I have looked for ever since.\r' \
  '\r' \
  'They must have asked me something\r' \
  'at the border\r' \
  'I was admitted\r' \
  'somehow\r' \
  'and behind me swung the stamped tin shutter\r' \
  'across the very sky\r' \
  'and I went free\r' \
  'to find myself\r' \
  'mazed in Victorian brick\r' \
  'amid sweet tea with milk\r' \
  'and smoke from a cigarette called a Black Cat\r' \
  'and every unknown brand of chocolate\r' \
  'and girls with blunt-cut bangs\r' \
  'not even Americans\r' \
  'looking down from high narrow windows\r' \
  'on the melting snow\r' \
  'of the city undreamed\r' \
  'and on the revealed grace\r' \
  'of the mechanism;\r' \
  'no round trip.\r' \
  '\r' \
  'They tore down the bus station\r' \
  "there's chainlink there\r" \
  'no buses stop at all\r' \
  "and I'm walking through Chiyoda-ku\r" \
  'in a typhoon\r' \
  'the fine rain horizontal\r' \
  "umbrella everted in the storm's Pacific breath\r" \
  'tonight red lanterns are battered,\r' \
  '\r' \
  'laughing,\r' \
  'in the mechanism.  '

# First permutation. Generated sequence is:
# [ 5, 0, 3, 6, 1, 4, 7, 2 ]
InvPermutation_A = [ (((pos * 3) + 5) % 8) for pos in range(8) ]

#
# Second permutation. Generated sequence is:
# [ 6, 3, 0, 5, 2, 7, 4, 1 ]
InvPermutation_B = [ (((pos * 5) + 6) % 8) for pos in range(8) ]

def Permute(byte, table):
  val = 0
  for pos in range(8):
    if byte & (1 << pos):
      val |= (1 << table[pos])
  return val

def EncryptBlock(block):
  if len(block) != 3:
    raise ValueError("Bad block size. Must be three bytes")
  
  # Convert bytes to numbers
  (d, e, f) = [ ord(byte) for byte in block ]
  
  # Inverse permute every byte
  d = Permute(d, InvPermutation_B)
  e = Permute(e, InvPermutation_B)
  f = Permute(f, InvPermutation_B)
    
  # Pack the three 8-bit bytes into two 12-bit messages
  plaintext_msg1 = ((e & 0x0f) << 8) | ((d & 0xff)     )
  plaintext_msg2 = ((f & 0xff) << 4) | ((e & 0xf0) >> 4)

  # RSA encrypt the two 12-bit messages
  ciphertext_msg1 = pow(plaintext_msg1, 3491, 4097)
  ciphertext_msg2 = pow(plaintext_msg2, 3491, 4097)
  
  # Unpack the two 12-bit messages into three 8-bit bytes
  a = ((ciphertext_msg1 & 0xff)      )
  b = ((ciphertext_msg1 & 0xf00) >> 8) | ((ciphertext_msg2 & 0x00f) << 4)
  c = ((ciphertext_msg2 & 0xff0) >> 4)
  
  # Inverse permute the middle byte
  b = Permute(b, InvPermutation_A)
  
  # Convert the bytes into characters
  return ''.join([chr(c) for c in (a, b, c)])

ciphertext = ''

for i in range(0,len(plaintext),3):
  block = plaintext[i:i+3]
  ciphertext += EncryptBlock(block)

# Print the ciphertext as hexadecimal characters because it contains
# unprintable characters.
print ciphertext.encode('hex')