javaSampleInput created by IanMcT - https://repl.it/@IanMcT/javaSampleInput

Main.java

import java.util.*;
class Main {
  public static void main(String[] args) {
    Scanner scanner = new Scanner(System.in);
    System.out.println("Enter a number");
    int n = scanner.nextInt(); // read an integer from input stream.
    System. out. println(n); // print n.
    System.out.println("Hello world!");
  }
}