Hedy works at horse stables. All horses are taken out to their paddocks in the morning. It is possible to take more than one horse at a time but only three at most. It usually takes at least five minutes to take a horse to its paddock. A horse called Adolf, however, is old and slow, so it takes at least 10 minutes. Boris is a bit wild, so only one other horse can be taken at the same time with him. Carlos and Doris do not get along at all, and cannot be taken at the same time. It is the same with Einar and Fjalar. Gunnar loves humans but does not like other horses and has to be taken alone. If Hedy wants to take the horses to their paddocks as quickly as possible, what is the minimum amount of time required?