How many years passed between the signing of the Treaty of Brömsebro and the Treaty of Roskilde?
return signing of   the  Treaty  of Brömsebro ;return Treaty  of   Roskilde ;return when  was  #1 ;return when  was  #2 ;return year of   #3 ;return year of   #4 ;return difference of   #6 and  #5
['select', 'select', 'project', 'project', 'project', 'project', 'arithmetic']