array(3) {
  [1]=>
  array(2) {
    [0]=>
    int(2772)
    [1]=>
    int(3991)
  }
  [9]=>
  array(2) {
    [0]=>
    int(7595)
    [1]=>
    int(9701)
  }
  [21]=>
  array(1) {
    [0]=>
    int(9596)
  }
}