How many years after wild grains began being harvested was the potato domesticated, at its earliest?
return wild grains began being harvested ;return the  potato was  domesticated ;return year of #1 ;return years of #2 ;return the  lowest of #4 ;return the  difference of #5 and  #3
['select', 'select', 'project', 'project', 'aggregate', 'arithmetic']