How many days passed between the fortress running out of food and gunpowder, and the fortress being stormed and captured?
return the  fortress running out of food and   gunpowder ;return the  fortress being stormed and   captured ;return day of #1 ;return day of #2 ;return the  difference of #4 and   #3
['select', 'select', 'project', 'project', 'arithmetic']