Accepting the value of a string variable as null automatically while trying to give input in Java using scanner class

Question

Why can't BlueJ (version - 4.2.2) take an input from the user for the latter string (s2) in the following code snippet?

import java.util.Scanner;
public class Test{
    public static void main(String[]args){
    Scanner sc = new Scanner(System.in);
    String s1 = sc.nextLine();
    int s = sc.nextInt();
    String s2 = sc.nextLine();
    }
}