The single-seat constituencies are decided by plurality, and the proportional seats are handed out in each "block" constituency to party lists proportionally (by the D'Hondt method) to their share of the vote. Each voter votes twice, once for a candidate in the local constituency, and once for a party in the regional "block" constituency. In a parallel system, there is no link between votes in one tier and seat numbers in the other; but so-called of one candidate in both tiers simultaneously are allowed. If such dual candidates lose in the majoritarian tier, they still have a chance to be elected in the proportional block. Parties may also place dual district and block candidates on the same list rank; in that case, the system determines the order of candidates.