How to validated multiplicate number in laravel

i am trying to post form with number as 5 or 10 or 15 or 20 like multiplication table of 5

i want to validated if user enter 4 or 3 or 2 or 1 return error if user enter 5 or 10 request accept and go to next

i really can't find on google something like this

here is key and value

{"1":"100","2":"0","3":"0","4":"0","5":"0","6":"0","7":"0","8":"300","9":"0","10":"0","11":"0","12":"0","13":"0","14":"0","15":"0","16":"0","17":"0","18":"0","19":"0","20":"0","21":"0","22":"0","23":"0","24":"0","25":"0","26":"0","27":"0","28":"0","29":"0","30":"0","31":"0","32":"0","33":"0","34":"0","35":"0","36":"0","37":"0","38":"0","39":"0","40":"0","41":"0","42":"0","43":"0","44":"0","45":"0","46":"0","47":"0","48":"0","49":"0","50":"0","51":"0","52":"0","53":"0","54":"0","55":"0","56":"0","57":"0","58":"0","59":"0","60":"0","61":"0","62":"0","63":"0","64":"0","65":"0","66":"0","67":"0","68":"0","69":"0","70":"0","71":"0","72":"0","73":"0","74":"0","75":"0","76":"0","77":"0","78":"0","79":"0","80":"0","81":"0","82":"0","83":"0","84":"0","85":"0","86":"0","87":"0","88":"0","89":"0","90":"0","91":"0","92":"0","93":"0","94":"0","95":"0","96":"0","97":"0","98":"0","99":"0","100":"0"}

via Chebli Mohamed