PARIS (AP).- A broken alarm system made it as easy as 1-2-3: A masked intruder clipped a padlock, smashed a window and stole a Picasso, a Matisse and three other masterpieces from a Paris museum Thursday — a $123 million haul that is one of the world’s biggest art heists. Offloading the artwork may prove a tougher task, however, with Interpol and collectors worldwide now on high alert. In what seemed like an art thief’s fantasy, the alarm system had been broken since March in parts of the Paris Museum of Modern Art, according to the city’s mayor, Bertrand Delanoe. The museum, in a tony neighborhood across the Seine River from the Eiffel Tower, reopened in 2006 after spending $18 million (euro15 million) and two years upgrading its security system. Spare parts had been ordered to fix the alarm but had not yet arrived, the mayor said in a statement. So with no alarm to worry about, a lone masked intruder entered the museum about 3:50 a.m., said Christophe Girard, deputy cultu