if ($a[0] =~ /[A-Za-z]/) {
        $a[0] ne $b[0] ? $a[0] cmp $b[0] : ($a[1] <=> $b[1] ? $a[1] <=> 
+$b[1] : $a[2] <=> $b[2]);
    } else {
        $a[0] != $b[0] ? $a[0] <=> $b[0] : ($a[1] <=> $b[1] ? $a[1] <=> 
+$b[1] : $a[2] <=> $b[2]);
    }