You are given a record of the historical prices of an investment asset from the last N days. Analyze the record in order to calculate what could have been your maximum income. Assume you started with one asset of this type and could hold at most one at a time. You could choose to sell $-$ the asset whenever you held one. If you did not hold an asset at some moment, you could always afford to buy an asset $($assume you had infinite money available$).$

What is the maximum income you could make?

Write a function:

int solution $($vector &A$)$:

that, given an array A of length N representing a record of prices over the last N days, returns the maximum income you could make. As the result may be large, return its last nine digits without leading zeros $($return the result modulo $1,000,000,000).$