sub belg4mit {
	my %H;
	my ($len, @k) = @_;
	my ($a,$b,$c) = (0)x3;
	while($len--) {
 		$H{(('a')x4,('b')x4,('c')x3)[$len]}
			+= $k[$len -1] << (8* ( ($len > 8 ? $len : $len - 1 )%4 ) );
	}
	return ($H{a}||0)+($H{b}||0)+($H{c}||0);
}