public class Ruler { public static void main(String[] args) { String ruler1 = " 1 "; String ruler2 = ruler1 + "2" + ruler1; String ruler3 = ruler2 + "3" + ruler2; String ruler4 = ruler3 + "4" + ruler3; String ruler5 = ruler4 + "5" + ruler4; System.out.println(ruler1); System.out.println(ruler2); System.out.println(ruler3); System.out.println(ruler4); System.out.println(ruler5); } }