<?php // your code goes here $arr = [1, 2, 3, 4, 5];
Standard input is empty
array(10) {
[0]=>
int(1)
[1]=>
int(1)
[2]=>
int(2)
[3]=>
int(2)
[4]=>
int(3)
[5]=>
int(3)
[6]=>
int(4)
[7]=>
int(4)
[8]=>
int(5)
[9]=>
int(5)
}