No wrong numbers

Mr. has a garage in S, and now he has just bought another garage in P. P is only five miles from S, but Mr. can not get telephone for his new garage, so he just bought twelve pigeons. Yesterday a pigeon carried  the first message from P. to S. The bird covered the distance in three minutes. Up to now, Mr. has sent great many requests for spare parts and other urgent messages from one garage to the other. In this way, he has begun his own private telephone service.