Searching an element in an ArrayList using inbuilt function (Contains)

import java.util.*;

public class LinkeListOper1 {

public static void main(String args[]) {

LinkedList<String> ll = new LinkedList<>();

ll.add("john");

ll.add("kiyan");

ll.add("kayna");

ll.add("cristy");

Scanner sc = new Scanner(System.in);

System.out.println("Enter a character to be searched");

String str = sc.nextLine();

if (ll.contains(str)) {

System.out.println("True");

} else {

System.out.println("false");

}

}

}