nm = gets.split
n = nm[0].to_i
m = nm[1].to_i
a = gets.split.map(&:to_i)
s = Array.new(n)
n.times do |i|
    s[i] = i + 1
end
m.times do |i|
    ai = a[i] - 1
    t = s[ai]
    j = ai
    while j > 0 do
        s[j] = s[j - 1]
        j -= 1
    end
    s[0] = t
end
puts s[0]