MASSAPEQUA PARK - For the first time in two years, Long Islanders will receive a boost in their Social Security benefits. Federal legislators voted to increase the benefits by 3.6 percent starting in Jan. 2012, giving senior citizens an extra $43 per month, or $516 per year. Some say they are pleased with the plan, even though they find it hard to believe given how expensive it is to live on Long Island. "It's not as much as I would like, but we have to be happy with what we've got," says Christopher Widelo, of AARP. However, the cost-of-living improvements could be lost to higher Medicare premiums, which are deducted from Social Security payments.