Max value java streams

import java.util.*;
class Main {
    public static void main(String[] args) {
        System.out.println("Hello World!");
        List<Integer> list = new ArrayList<>(Arrays.asList(23,55,77,99));
        int max = list.stream().mapToInt(Integer::intValue).max().orElseThrow();
        System.out.println(max);
    }
}