title: Make all combination from 3 text file in PHP
body: <p>Is there any valid soft for creating all combination from 3 text file ?
  Example -</p>
  
  <p>1.txt:
  1
  2</p>
  
  <p>2.txt:
  3
  4</p>
  
  <p>3.txt:
  5
  6</p>
  
  <p>Results:
  13
  14
  15
  16
  23
  24
  25
  26</p>