sum of the neighbour

for (int i = 0; i < columnLength; i++) {
            for (int j = 0; j < rowLength; j++) {
                int up = i + 1;
                if (up == columnLength) {
                    up = 0;
                }
                int down = i - 1;
                if (down < 0) {
                    down = columnLength - 1;
                }
                int right = j + 1;
                if (right == rowLength) {
                    right = 0;
                }
                int left = j - 1;
                if (left < 0) {
                    left = rowLength - 1;
                }

                matrix2[i][j] = matrix1[up][j] + matrix1[down][j] + matrix1[i][right] +  matrix1[i][left];
            }
        }


/* print matrix2 ,
 Sample Input:
9  5  3
0  7  -1
 -5  2  9

 Sample Output:
3  21  22
 10  6  19
 20  16  -1 */