Given that two int variables, total and amount, have been declared, write a loop that reads non-negative values into amount and adds them into total. The loop terminates when a value less than 0 is read into amount. Don't forget to initialize total to 0. Instructor Notes: Be sure to complete exercises 10087 and 10088 before attempting 10089. "Reads non-negative values into amount" means that values are read (input) into amount from stdin. As long as a given input value is non-negative, the code keeps adding the result into total. But, if a negative value is read, then the loop terminates, without adding that negative result into total. The negative value is known as a "sentinel" value, which means a value that signals something rather than having a quantitative meaning.