Customer Service Desk Queue

You are simulating a customer service desk in a store. Customers arrive at random intervals, and each spends a random amount of time being served. Implement a program that reads a list of arrival and service times, and prints the total time spent being served for all customers. The input consists of multiple lines, each with an integer representing the arrival time and another integer representing the service time. The input ends when you reach the end of file (EOF). Each output should be printed on a new line with the total time. Example Input: 0 3 1 9 5 6 Example Output: 9