n, m = gets.chomp.split.map(&:to_i)
a = []
n.times{a << gets.to_i}
vote = Array.new(n, 0)
m.times{
    b = gets.to_i
    v = nil
    a.each_with_index{|cost, i|
        if cost <= b
            v = i
            break
        end
    }
    vote[v] += 1
}
puts vote.index(vote.max) + 1
