Yet Another Profit Problem

Cooper is a shopkeeper with a list of items. Any item in the list is a number from 0 to 9 inclusive. A string $S$ represents the list of items in which the $i$-th element is given by $S_i$. You are given two arrays $A$ and $B$ of size $10$ such that the cost price of an item $i$ is denoted by $A_i$ whereas the selling price of an item $i$ is denoted by $B_i$. For example, cost price of an item '3'