HAVANA (AP) — Late one balmy spring night during Havana's 12th Biennial, young working-class men and women lounged on a stretch of sand dotted with folding chairs and umbrellas, an artificial beach created as an art installation on the capital's Malecon seaside promenade.Meanwhile, at Sotheby's auction house in New York, the beach's 40-year-old creator, Arles del Rio, sold another piece featured at the last biennial for $11,875, more than 40 times the annual salary of an ordinary Cuban.