Each district i needs minimum p_i voters with strict majority for winner. Minimum winner votes = floor(p_i/2)+1, minimum loser votes = 0, but total must be ≥ p_i.

Allocate mandatory votes first: district i gets p_i total with correct winner majority. Sum minimum A-votes needed for all 0-districts, same for B-votes for 1-districts.

After mandatory allocation, remaining surplus voters can go anywhere. Feasibility check: total mandatory votes ≤ x+y, each party's minimum ≤ available voters of that party.