init: 

  # Setting the storage value
  contract.storage[999] = 3

code:

  # Using the storage on the call
  a = contract.storage[999]
  
  if a > 0: 
      contract.storage[999] = a - 1

      # call to myself:
      send((tx.gas / 10 * 8), contract.address, 0)
  else: 
     stop