if (a == 1) {
  System.out.println(a);
  x = 3;
  b = b + x;
} else if (a == 2) {
  System.out.println(a);
  x = 6;
  y = y + 10;
  b = b + x;
} else {  // a == 3
  System.out.println(a);
  x = 9;
  b = b + x;
}