n, k = read_line.split.map(&.to_i64)
a = read_line.split.map(&.to_i)
b = read_line.split.map(&.to_i)
cnt = Array.new(n) do |i|
  divs = [] of Int32
  d = 1
  while d * d < a[i]
    if a[i] % d == 0
      divs << d << a[i] // d
    end
    d += 1
  end
  if d * d == a[i]
    divs << d
  end
  c = [] of Tuple(Int32, Int64)
  divs.sort.each do |d|
    rem = b[i] % d
    use = rem == 0 ? 0 : d - rem
    while c.size > 0 && c[-1][1] >= use
      c.pop
    end
    c << {d, use.to_i64}
  end
  c
end
lo = 1
hi = a.min + 1
while hi - lo > 1
  mid = (lo + hi) // 2
  need = n.times.sum do |i|
    idx = cnt[i].bsearch_index { |x, _| x[0] >= mid }.not_nil!
    cnt[i][idx][1]
  end
  if need <= k
    lo = mid
  else
    hi = mid
  end
end
puts lo