How many days after the Soviets made their 2nd offer did the Polish make their counteroffer?
return the  Soviets made their  2nd offer ;return the  Polish did make their  counteroffer ;return when  was  #1 ;return when  was  #2 ;return difference of #3 and  #4 in  days
['select', 'select', 'project', 'project', 'arithmetic']