shuffles(nCards, iCut) 

  for i from 0 to nCards
    deck[i] = i

  for i from 0 to nCards
    perfect_shuffle(deck, iCut)
    for j from 0 to nCards
      if periods[j] == null and deck[j] == j
        periods[j] = i+1

  return least_common_multiple(periods)