new_contents: def coin_change(left, coins, count):
      if left == 0:
          return count
  
      if not coins:
          return 0
  
      coin, *coins_left = coins
      return sum(coin_change(left-coin*i, coins_left, count+1)
                 for i
                 in range(0, left//coin))
  
  
  if __name__ == '__main__':
      coins = [200, 100, 50, 20, 10, 5, 2, 1]
      total = 200
      ans = coin_change(total, coins, 0)
  
subject: Work on 31 coin sums