big_w = gets.to_i 
num = gets.to_i 
n_w = gets.to_s 
n_w2 = n_w.split(" ") 

if num <= n_w2.length
    n_w2.slice!(num..n_w2.length)
end

n_w2.map!(&:to_i)

i = 0
ans = 0
n_w2.sort.each_with_index do |a, index|
    if i + a == big_w
        ans = index + 1
    elsif i + a >= big_w
        ans = index
        break
    else
        i += a
    end
end
puts ans