How many years after the death of Martin Luther did the Schmalkaldic War start out as a conflict between two German Lutheran rulers?
return the  death of Martin Luther ;return the  Schmalkaldic War did start out as a conflict between two German Lutheran rulers ;return year of #1 ;return year of #2 ;return difference of #3 and  #4
['select', 'select', 'project', 'project', 'arithmetic']