High-Flying Advertising, Inc., contracted with Big Burger Restaurants to fly an advertisement above the Connecticut beaches. The advertisement offered $5,000 to any person who could swim from the Connecticut beaches to Long Island across the Long Island Sound in less than a day. McElfresh saw the streamer and accepted the challenge. He started his marathon swim that same day at 10 a.m. After he had been swimming for four hours and was about halfway across the sound, McElfresh saw another plane pulling a streamer that read, “Big Burger revokes.” Is there a contract between McElfresh and Big Burger? If there is a contract, classify it by types.