1821
a b - 1 bomber dropped four 2 , 000 - pound bombs on a building in a residential area of baghdad after getting intelligence reports senior officials were meeting there , possibly including saddam hussein and his sons .
 building: target; bomber: instrument; bombs: instrument
Given event type and trigger, please tell me the arguments of all the listed option. Output format is "name1: role1; name2: role2". 
Event type: attack 
  Option: victim, attacker, place, target, instrument 
Text: {0} 
Answer:
 building: target; bomber: instrument; bombs: instrument