// Another way to solve the sentinel loop problem.

import java.util.*;

public class SentinelSum2 {
    public static void main(String[] args) {
        Scanner console = new Scanner(System.in);

        int sum = 0;
        int number = 1;   // dummy value (anything but -1, so loop will start)
        
        while (number != -1) {
            System.out.print("Enter a number (-1 to quit): ");
            number = console.nextInt();
            
            // don't add the number to the total if it is the sentinel
            if (number != -1) {
                sum += number;
            }
        }
        
        System.out.println("The total was " + sum);
    }
}