Objects and Collections - General Questions

What is the output of the following program?

import java.util.*;
public class Main {
    public static void main(String[] args) {
        List<String> l = new ArrayList<>(List.of("a", "b", "c"));
        l.remove(1);
        l.add(0, "z");
        System.out.println(l);
    }
}

What is the output of the following program?

import java.util.*;
public class Main {
    public static void main(String[] args) {
        Deque<Integer> st = new ArrayDeque<>();
        st.push(1); st.push(2); st.push(3);
        System.out.println(st.pop() + " " + st.peek());
    }
}

Which collection keeps insertion order and allows fast lookup by key?