A 3 x 3 grid of integers is stored in a 2D array. Write a program that inputs 9 integers **row by row** (the first three inputs fill row 1, the next three fill row 2, and so on). Output two lines: 1. The sum of the main diagonal (top-left to bottom-right). 2. The sum of the anti-diagonal (top-right to bottom-left). For example, the grid 1 2 3 / 4 5 6 / 7 8 9 has a main diagonal sum of 15 and an anti-diagonal sum of 15.