What event happened first, the Ottomans signing a treaty in Athens, of Serbia signing a treaty in Constantinople?
return the  Ottomans signing  a treaty  in  Athens ;return Serbia signing  a treaty  in  Constantinople ;return when  was  #1 ;return when  was  #2 ;return which is lowest of #3 ,  #4
['select', 'select', 'project', 'project', 'comparison']