How to Solve Minimum Money Required Before Transactions Problem

You are given a 0-indexed 2D integer array transactions, where transactions[i] = [costi, cashbacki]. The array describes transactions, where each transaction must be completed exactly once in some order. At any given moment, you have a certain amount of money. In order to complete transaction i, money >= costi must hold true. After performing a transaction, money becomes money - costi + cashbacki. Return the minimum amount of money required before any transaction so that all of the transactions can be completed regardless of the order of the transactions.