Excel - writing a complex formula : i have a bunch of numbers and i want to write one formula in cell "AJ1" to reach the number "77"  (see AJ2 in sample file) 

Maybe it can be a VB macro to do is, i dont know... 

[Sample File][1]

Thank you for your time & help. 

  [1]: https://drive.google.com/open?id=1783moPPd4cPElL0-dbmlXXUjZdDNk47N