Exercise 1 (a) Write a java program to determine if a number is perfect. Your program must read the give:n integer and print whether it is perfect or not. A perfect number is defined as a positive integer (>0) such that the sum of its factors (including 1, but not the number itself), add up to the number. For example 6 1+2+3) is a perfect number Use the following template public class Exla! public static void main(String[] args)\ //rest of the code here (b) Modify the above program so that it uses a method isPerfect to determine if a given integer is perfect or not public class Exlb! public static void main(String[] args)l //rest of the code here public static boolean isPerfect(int n)\ //code here (c) Modify l(b) to print all perfect numbers from 1 to 10,000. Call this program: Exlc (d) Determine the execution time for the core part of the program (finding all perfect numbers between 1 and 10,000) in 1(c). You can use the following code template to obtain the execution time long startTime, endTime, executionime; startTime = System.currentTimeMillis(); //code segment endTime= Syst r 11 i s(); executionTime -endTime - statime The above segment will give the time for executing the code segment in milliseconds. Call this program: Erld