public class MaxNetVulnerability {
    static int getMaxNetVulnerability(int[][] vulnerability) {
        int n = vulnerability.length;
        int m = vulnerability[0].length;

        int maxNetVulnerability = Integer.MIN_VALUE;

        for (int row1 = 0; row1 < n; row1++) {
            for (int row2 = row1 + 1; row2 < n; row2++) {
                int[][] subsetGrid = new int[2][m];

                subsetGrid[0] = vulnerability[row1];
                subsetGrid[1] = vulnerability[row2];

                int[] maxInColumns = new int[m];

                for (int col = 0; col < m; col++) {
                    int max = Integer.MIN_VALUE;
                    for (int row = 0; row < 2; row++) {
                        max = Math.max(max, subsetGrid[row][col]);
                    }
                    maxInColumns[col] = max;
                }

                int minMaxInColumns = Integer.MAX_VALUE;
                for (int max : maxInColumns) {
                    minMaxInColumns = Math.min(minMaxInColumns, max);
                }

                maxNetVulnerability = Math.max(maxNetVulnerability, minMaxInColumns);
            }
        }

        return maxNetVulnerability;
    }

    public static void main(String[] args) {
        int[][] vulnerability = {
                {1, 3, 1},
                {3, 1, 1},
                {1, 2, 2},
                {1, 1, 3}
        };
        int maxVulnerability = getMaxNetVulnerability(vulnerability);
        System.out.println("Maximum possible net vulnerability: " + maxVulnerability);
    }
}