Initially, how many books belong to the child with the least number of book

Altogether, there are 240 books owned by 3 children. If Ace gives Bea 10 books, Bea gives Cec 20 books, Cec give Dee 30 books and Dee gives Ace 40 book. Then each has the same number of books. Initially, how many books belong to the child with the least number of book?