What will be the output of this code?

What will be the output of this code?

public class Student {
  private int age;
  public int getAge() {
    return age;
  }
  public void setAge(int age) {
    this.age = age;
  }
  public static void main(String[] args) {
    Student s = new Student();
    System.out.println(s.getAge());
  }
}