N = gets.to_i
A = gets.split.take(N).map(&:to_i)
M = gets.to_i
B = gets.split.take(M).map(&:to_i)

a = A.sort_by!{|v|-v}
b = B.sort_by!{|v|-v}
used = [false] * N

b.each_with_index{|box, i|
  a.each_with_index{|x, j|
    next if used[j] || box < x
    box -= x
    used[j] = true
  }
  if used.all?
    p i + 1
    exit
  end
}
p -1