N = gets.to_i
A = gets.split.take(N).map(&:to_i).sort_by{|v|-v}
M = gets.to_i
B = gets.split.take(M).map(&:to_i).sort_by{|v|-v}

ans = A.permutation(N).inject(9e9){|r, order|
  res = 9e9
  B.each_with_index{|box, j|
    while !order.empty?
      break if box < order[0]
      box -= order.shift
    end
    if order.empty?
      res = j + 1
      break
    end
  }
  [r, res].min
}
p ans > M ? -1 : ans