the number of cells that can be filled by the process of filling, starting from the blank grid (i.e. only one cell in this row can be a 2, so it must be a 2)
Osatuz bete daitezkeen laukien kopurua, hutsik dagoen saretatik hasiz (adibidez, lerro honetako lauki bakarrean joan daiteke 2a, beraz 2a da).