$nbArguments = $#ARGV + 1; 
print "number of arguments: $nbArgumentsn"; 
exit(1) unless $nbArguments == 5;

##</code><code>##

$a = $ARGV[0]; 
$operation = $ARGV[1]; 
$b = $ARGV[2]; 
$c = $ARGV[3]

##</code><code>##

$val1 = $ARGV[0]; 
$operation1 = $ARGV[1]; 
$val2 = $ARGV[2]; 
$operation2 = $ARGV[3]
$val3=$ARGV[4]