[10 marks] Write a Java program to find all pairs of elements in an array of integer values which their sum is equal to a specified number. Your program should ask user to input the array values and the required sum. Then it displays all possible pairs. Sample Run: Enter the elements of an integer array: 2,7, 4, -5, 11, 5, 20 Enter the required sum: 15 Pairs of elements and their sum are: 4+11=15 1-5+20-15