import java.util.concurrent.*;

public class ThreadPool {
    public static int findMax(int[][] matrix, int numThreads) throws InterruptedException, ExecutionException {       
        ExecutorService executor = Executors.newFixedThreadPool(numThreads);
        int rows = matrix.length;
        int cols = matrix[0].length;
        int chunkSize = rows / numThreads;
        Future<Integer>[] futures = new Future[numThreads];

        for (int i = 0; i < numThreads; i++) {
            int startRow = i * chunkSize;
            int endRow = (i == numThreads - 1) ? rows : startRow + chunkSize;
            futures[i] = executor.submit(() -> findMaxInRange(matrix, startRow, endRow));
        }

        int max = Integer.MIN_VALUE;
        for (Future<Integer> future : futures) {
            int localMax = future.get();
            if (localMax > max) {
                max = localMax;
            }
        }

        executor.shutdown();
        return max;
    }

    private static int findMaxInRange(int[][] matrix, int startRow, int endRow) {
        int max = Integer.MIN_VALUE;
        for (int i = startRow; i < endRow; i++) {
            for (int j = 0; j < matrix[i].length; j++) {
                if (matrix[i][j] > max) {
                    max = matrix[i][j];
                }
            }
        }
        return max;
    }
}