!string.equals(string) turns false result

In a part of my program, I put a while loop to repeatedly ask for inputs. There is an option to type in letter "F" and break the loop. This is my program:

public class Example {

public static void main(String[] args) {
    int x = 0;
    ArrayList Numbers = new ArrayList();
    while (x==0) {
        System.out.println("Type your number:");
        Scanner s = new Scanner(System.in);
        if (s.equals("f") || s.equals("F")) {
            x = 1;
        }
        else if (!s.equals("f") && !s.equals("F")) {
            int n = Integer.parseInt(s.next());
            Numbers.add(n);
        }
    }
    
}}

When I run the program, I type some numbers and then type "F". I see this error:

Exception in thread "main" java.lang.NumberFormatException: For input string: "F"
at java.base/java.lang.NumberFormatException.forInputString(NumberFormatException.java:68)
at java.base/java.lang.Integer.parseInt(Integer.java:652)
at java.base/java.lang.Integer.parseInt(Integer.java:770)
at Example.main(Example.java:13)

I believe the String "F" can pass through my else if but I don't know why. How can I solve this?