Two friends, Abe and Betty, are planning for their retirement. Both are 20 years old and plan on retiring in 30 years with $1 million each. Betty plans on making annual deposits beginning in one year (total of 30 deposits) while Abe plans on waiting and then depositing twice Betty’s deposits. If both can earn 5 percent per year, how long can Abe wait before he has to start making his deposits?