N, M, P, Q = gets.split.map(&:to_i)

ans = 0

Q.times do
  x, f = gets.split.map(&:to_i)

  if x % P == 0
    if f == 0
      puts M
    else
      puts 0
    end
  else
    t = f * x.pow(P - 2, P) % P

    if t == 0
      if P > M
        puts 0
      else
        ok = 1
        ng = M + 1

        while (ok - ng).abs >= 2
          k = (ok + ng) / 2

          if P * k <= M
            ok = k
          else
            ng = k
          end
        end

        puts ok
      end
    else
      if t > M
        puts 0
      else
        ok = 1
        ng = M + 2

        while (ok - ng).abs >= 2
          k = (ok + ng) / 2

          if P * (k - 1) + t <= M
            ok = k
          else
            ng = k
          end
        end

        puts ok
      end
    end
  end
end