sub solution {
    my @num=@_;
    my @opr=('+','-','*','/');
    my $step;
    my $output;
    my $exp;
    my $a;
    my $b;
    my $c;
    foreach $step (1..8) {                                      #loop for order of operator
        foreach $a (0..3) {                                      #loop for math operator
            foreach $b (0..3) {                                      #loop for math operator
                foreach $c (0..3) {                                      #loop for math operator
                    if ($step==1||$step==4||$step==6||$step==7) { $output.='('; }
                    $output.=$num[0];

                    $output.=$opr[$a];
                    if ($step==2||$step==3) { $output.='('; }
                    $output.=$num[1];
                    if ($step==1||$step==6) { $output.=')'; }

                    $output.=$opr[$b];
                    if ($step==1||$step==5) { $output.='('; }
                    $output.=$num[2];
                    if ($step==2||$step==4) { $output.=')'; }

                    $output.=$opr[$c];
                    $output.=$num[3];
                    if ($step==1||$step==3||$step==5||$step==7) { $output.=')'; }
                    $exp=eval($output);

                    if ($exp==24) {
                        ++$j;
                        print "[$j]   ::   $output\n";
                    }
                    $output='';
                }
            }
        }
    }
}

my $a;
my $b;
my $c;
my $d;
my @num;
$j=0;

if ($^O eq 'MSWin32') { system('cls'); }
else { system('clear'); }
print "\n   === [24 Points : Solution] ===\n";
print "    By AssazziN [14/05/2011] \n\n";
print "   Enter number (Ex. 1 3 4 6) : ";
chomp($input=<STDIN>);
($num[0],$num[1],$num[2],$num[3])=$input=~/^(\d)\s(\d)\s(\d)\s(\d)$/;
unless ($num[0]&&$num[1]&&$num[2]&&$num[3]) { print "Format error !"; exit(0); }



foreach $a (0..3) {
    foreach $b (0..3) {
        if ($b==$a) { next; }
        foreach $c (0..3) {
            if ($c==$a||$c==$b) { next; }
            foreach $d (0..3) {
                if ($d==$a||$d==$b||$d==$c) { next; }
                solution($num[$a],$num[$b],$num[$c],$num[$d]);
            }
        }
    }
}
print "Not found solution !!\n" if ($j==0);

## Code Grean Grean By AssazziN