public static int[] solution(int[][] matrix) {
        int rows = matrix.length;
        int cols = matrix[0].length;
        int[] result = new int[2];
        int minDifference = Integer.MAX_VALUE;

        for (int i = 0; i < rows - 1; i++) {
            for (int j = 0; j < cols - 1; j++) {
                int[] avgs = {
                        average(matrix, 0, i, 0, j),
                        average(matrix, 0, i, j + 1, cols - 1),
                        average(matrix, i + 1, rows - 1, 0, j),
                        average(matrix, i + 1, rows - 1, j + 1, cols - 1)
                };

                int minAvg = Integer.MAX_VALUE, maxAvg = Integer.MIN_VALUE;
                boolean isMinusOne = false;
                for (int avg : avgs) {
                    if (avg != -1) {
                        minAvg = Math.min(minAvg, avg);
                        maxAvg = Math.max(maxAvg, avg);
                    } else if (avg == -1) {
                        isMinusOne = true;
                        break;
                    }
                }
                if (isMinusOne) continue;

                if (minAvg != Integer.MAX_VALUE && maxAvg != Integer.MIN_VALUE) {
                    if (maxAvg - minAvg <= minDifference) {
                        minDifference = maxAvg - minAvg;
                        result[0] = i;
                        result[1] = j;
                    }
                }
            }
        }

        return result;
    }

    public static int average(int[][] matrix, int r1, int r2, int c1, int c2) {
        int sum = 0;
        int count = 0;
        for (int i = r1; i <= r2; i++) {
            for (int j = c1; j <= c2; j++) {
                if (matrix[i][j] >= 0) {
                    sum += matrix[i][j];
                    count++;
                }
            }
        }
        return count == 0 ? -1 : sum / count;
    }