The city of Emden called on its possession Oldersum how many years before the Prince called in reinforcements from Denmark to help with the bettle?
return the  city of Emden called on its possession Oldersum ;return the  Prince called in  reinforcements from  Denmark to help with the bettle ;return year of #1 ;return year of #2 ;return difference of #3 and  #4
['select', 'select', 'project', 'project', 'arithmetic']