solve question using recursion [JAVA]

Question 1: solution must be with recursion. for a two dimensional array of positive integers how can I return the longest path (steps), so that the value in each cell of the longest path is from descending series of integers and the difference between each cell and cell is a given number (num). Assumes that n is a value of the cell so (n - num) is a positive number (not zero). can't use any loops (for,while,...etc) the Method: public static int longestPath(int matrix[][],int number){... return(__overloading__); } For example: int number=1; int [][]matrix ; matrix = new int[][]{{8, 15, 20, 33, 35}, {60, 59, 58, 32, 31}, {59, 17, 57, 56, 55}, {55, 15, 13, 58, 16}}; [login to view URL](" longestPath= "+ longestPath(matrix, num)); } if we search for the longest path with the difference number = 1 1-in the cell matrix[0][3] the path long is 3 and the value in this path is 33 -> 32 -> 31 ends in matrix[1][4] 2-in the cell matrix[1][0] the path long is for 6 and the value in the path 60 -> 59 -> 58 -> 57 -> 56 -> 55 ends in matrix[2][4] 3-in the cell matrix[1][0] the path long is 2 and the value in this path is 60 -> 59 ends in matrix[2][0] so the method must return the longest path witch its 6 if we search for the longest path with the difference number = 2 1-in the cell matrix[2][1] the path long is 3 and the value in this path is 17 -> 15 -> 13 ends in matrix[3][2] the method must return the longest path witch its 3.