/*
This program uses a "sentinel loop" to prompt for numbers
repeatedly until a certain "sentinel" value of -1 is entered.

The tricky part is making sure that the sentinel value doesn't
get added together with the other numbers.

EXPECTED OUTPUT:
Enter a number (-1 to quit): 95
Enter a number (-1 to quit): 87
Enter a number (-1 to quit): 43
Enter a number (-1 to quit): 29
Enter a number (-1 to quit): -1
The total was 254
*/

import java.util.*;

public class SentinelSum {
    public static final int SENTINEL = -1;

    public static void main(String[] args) {
        Scanner console = new Scanner(System.in);
        int sum = 0;
        
        // pulled first input out of loop
        System.out.print("Enter a number (" + SENTINEL + " to quit): ");
        int number = console.nextInt();

        while (number != SENTINEL) {
            sum += number;   // moved to start of while loop body
            System.out.print("Enter a number (" + SENTINEL + " to quit): ");
            number = console.nextInt();
        }
        
        System.out.println("The total was " + sum);
    }
}