8. (10 points) On the beach, there is a pile of chestnuts, which belong to four monkeys. They want to divide them equally. The first monkey came, waited and waited but the other monkeys did not come, so it divided the chestnuts into four equal piles, with one left over. It threw the leftover one into the sea and took one of the four piles. The second monkey came, and without waiting for the others, it divided the remaining chestnuts into four equal piles, with one left over. It threw away the leftover one and took one pile. The third monkey did the same, dividing the remaining chestnuts into four equal piles, throwing away the leftover one, and taking one pile. The last monkey also divided the remaining chestnuts into four equal piles, threw away the leftover one, and took one pile. So, the original pile of chestnuts had at least $\qquad$ chestnuts.