#! /usr/local/bin/perl  
$a=15;  
$b = ++$a -15;  
$c = $a++ - 15; 

print "The increment operation occurs first on the left side\n"; 
print "$b = ++$a - 15 results in $b equal ";    
print "$b\n";    
print "The increment operation occurs after other operations when on the right side\n";
print "$c = $a- - 15 results in $c equal ";
print "$c\n";