How many years passed between the Bolsheviks closing the Novodevichy Convent and religious services resuming on patron saint's days?
return the  Bolsheviks closing the Novodevichy Convent ;return religious services resuming on patron saints days ;return year of #1 ;return year of #2 ;return difference of #4 and  #3
['select', 'select', 'project', 'project', 'arithmetic']