Array Maximization

Given two arrays $A = \{a_1, a_2, ..., a_n\}$ and $B = \{b_1, b_2, ..., b_n\}$ each containing $n$ integers. At each unit time, every $a_i$ gets decreased by $b_i$, and then Alice puts an integer from array $A$ to set $C$ (which is initially empty), and erases the corresponding element from array $B$. This process repeats until arrays $A$ and $B$ are empty. Alice needs to find out the maximum sum